JP5532376B2 - Cleaning blade, image forming apparatus, process cartridge, and image forming method - Google Patents

Description

  The present invention relates to a cleaning blade, an image forming apparatus, a process cartridge, and an image forming method used in an image forming apparatus such as a printer, a facsimile machine, and a copying machine.

  Conventionally, in an electrophotographic image forming apparatus, unnecessary transfer residual toner adhering to a surface after transferring a toner image to a transfer paper or an intermediate transfer member is cleaned on an image carrier such as a photosensitive member as a member to be cleaned. It is removed by means of a cleaning device.

  As a cleaning member of this cleaning device, one that uses a strip-shaped cleaning blade is well known because it can generally be simplified in configuration and has excellent cleaning performance. This cleaning blade is composed of a strip-shaped elastic body such as polyurethane rubber. Then, the base end of the cleaning blade is supported by a support member, and the leading edge portion is pressed against the peripheral surface of the image carrier, and the toner remaining on the image carrier is damped and scraped off and removed.

  Further, in order to meet the recent demand for higher image quality, an image forming apparatus using a toner having a small particle diameter and a nearly spherical shape (hereinafter, polymerized toner) formed by a polymerization method or the like is known. This polymerized toner has characteristics such as higher transfer efficiency than conventional pulverized toner, and can meet the above requirements. However, it is difficult to remove the polymerized toner sufficiently from the surface of the image carrier using a cleaning blade, and there is a problem that cleaning failure occurs. This is because the polymerized toner having a small particle size and excellent sphericity passes through a slight gap formed between the blade and the image carrier.

  In order to suppress such slip-through, it is necessary to increase the cleaning pressure by increasing the contact pressure between the image carrier and the cleaning blade. However, when the contact pressure of the cleaning blade is increased, the frictional force between the image carrier 23 and the cleaning blade 262 increases as shown in FIG. 11A, and the cleaning blade 262 is pulled in the moving direction of the image carrier 23. As a result, the leading edge ridge line part 262c of the cleaning blade 262 is turned up. When the turned cleaning blade 262 is restored to its original state against the turn, abnormal noise may occur. Furthermore, if the cleaning is continued with the leading edge portion 262c of the cleaning blade 262 turned up, the cleaning blade 262 is separated from the leading edge portion 262c of the leading edge surface 262a of the cleaning blade 262 by several [μm] as shown in FIG. Local wear will occur at the site. If the cleaning is further continued in such a state, this local wear becomes large, and eventually the leading edge portion 262c is lost as shown in FIG. 11C. If the tip ridge line portion 262c is lost, the toner cannot be properly cleaned, resulting in poor cleaning.

Patent Document 1 describes that a cleaning layer made of a rubber member is provided with a surface layer made of a resin having a film hardness of pencil hardness B to 6H on at least a contact portion that makes contact with the image carrier. . By providing a surface layer having a coating hardness of pencil hardness B to 6H, which is harder than that of the rubber member, at the contact portion of the cleaning blade, the cleaning blade can be formed more than when the surface layer is not provided at the contact portion of the cleaning blade. Abrasion resistance can be increased. In addition, the friction coefficient of the contact portion of the cleaning blade with respect to the image carrier can be lowered, the frictional force generated between the image carrier and the contact portion of the cleaning blade can be reduced, and the tip ridge line portion of the cleaning blade can be reduced. Turn over can be suppressed well. Furthermore, since the surface layer of the pencil hardness of pencil hardness B to 6H is hard and hardly deformed, it is possible to further suppress the turning of the tip ridge line portion of the cleaning blade.
Japanese Patent No. 3602898

  However, if the surface layer wears and disappears due to rubbing with the image carrier over time, the tip ridge line portion of the rubber member comes into contact with the image carrier and the tip ridge line portion is turned up, resulting in poor cleaning. There is a fear.

  SUMMARY An advantage of some aspects of the invention is that a cleaning blade, an image forming apparatus, and a process cartridge capable of suppressing the turning and wear of a tip ridge line portion and maintaining cleaning properties for a long period of time are provided. And providing an image forming method.

In order to achieve the above object, a first aspect of the present invention is a cleaning blade that contacts a surface of a member to be cleaned and removes powder from the surface of the member to be cleaned. From the elastic blade, which covers a tip ridge line portion that is an angle between a lower surface of the blade facing the surface of the member to be cleaned of the body blade and a tip surface of the elastic blade in the longitudinal direction of the elastic blade. The Martens hardness in a cross section perpendicular to the longitudinal direction of the elastic body blade in the vicinity of the ridge line of the elastic body blade when measured at a load of 1 [mN] with a Vickers indenter is used. from 50 [[mu] m] inside and the blade lower surface elastic blade longitudinally from the surface in a direction orthogonal to the elastic blade longitudinal 50 [[mu] m] inside point 1.0 [N / mm ] Or 5.0 [N / mm ^2] or less, 100 [[mu] m from 100 [[mu] m] inside and the blade lower surface elastic blade longitudinally from distal end surface in a direction orthogonal to the elastic blade longitudinal ] It is characterized by being 0.4 [N / mm ² ] or more and 0.8 [N / mm ² ] or less at the inner part.
According to a second aspect of the present invention, there is provided a cleaning blade that contacts the surface of a member to be cleaned and removes powder from the surface of the member to be cleaned, a strip-shaped elastic blade, and a member to be cleaned of the elastic blade. A surface layer that is harder than the elastic blade and covers a tip ridge line portion that is an angle between a blade lower surface that is a surface facing the surface and a tip surface that is an end surface of the elastic blade in the longitudinal direction of the elastic blade. And an elastic body in the vicinity of the tip ridge line portion of the elastic blade when the angle of the tip ridge line portion is 60 [°] or more and 80 [°] or less and measured with a load of 1 [mN] by a Vickers indenter. Martens hardness of the blade cross section perpendicular to the longitudinal direction is at an angle position from the tip edge line portion on the center line 70 [[mu] m] inside of the tip edge line 1.0 [N / mm ^2] or more 5.0 [N / mm ² ] Or less, characterized in that the tip ridge portion is 140 [μm] 0.4 inside locations [N / mm ^2] or more 0.8 [N / mm ^2] or less on the center line is there.
The invention according to claim 3 is the cleaning blade according to claim 1 or 2, wherein the elastic blade impregnates the tip ridge portion with at least one selected from an isocyanate compound, a fluorine compound, and a silicone compound. And the friction coefficient of the tip ridge line portion is 0.5 or less.
According to a fourth aspect of the present invention, in the cleaning blade according to the first, second, or third aspect, the surface layer is made of an ultraviolet curable resin, and the layer thickness on the cut surface side of the surface layer is 1 [μm] or more and 50 [μm]. It is characterized by the following.
According to a fifth aspect of the present invention, in the cleaning blade according to the first, second, third, or fourth aspect, a rubber containing a urethane group is used as the elastic blade.
According to a sixth aspect of the present invention, there is provided an image carrier, a charging unit for charging the surface of the image carrier, a latent image forming unit for forming an electrostatic latent image on the surface of the charged image carrier, and the image carrier. A developing means for developing an electrostatic latent image formed on the body surface to form a toner image, a transfer means for transferring the toner image on the surface of the image carrier to a transfer body, and abutting on the surface of the image carrier; An image forming apparatus comprising a cleaning unit having a cleaning blade for removing residual toner adhering to the surface of the image carrier, wherein the cleaning blade according to claim 1, 2, 3, 4 or 5 is used as the cleaning blade. It is characterized by this.
The invention according to claim 7 integrally supports the image carrier and at least a cleaning means having a cleaning blade for removing residual toner adhering to the surface of the image carrier, and is attached to and detached from the image forming apparatus main body. In a free process cartridge, the cleaning blade according to claim 1, 2, 3, 4 or 5 is used as the cleaning blade.
The invention according to claim 8 forms a toner image on the image carrier, transfers the toner image from the image carrier to the transfer body, and then removes residual toner on the image carrier by a cleaning blade. In the image forming method to be removed, as the cleaning blade, a strip-shaped elastic blade, a blade lower surface that is a surface facing the surface of a member to be cleaned, and an end surface of the elastic blade in the longitudinal direction of the elastic blade The tip of the elastic blade is measured by a Vickers indenter with a load of 1 [mN], which is composed of a surface layer that is harder than the elastic blade and covers the edge of the tip that is an angle between the tip and the tip. Martens hardness at a cross-section perpendicular to the elastic blade longitudinal ridge near, elastic blade longitudinally 50 [[mu] m] inside and bullets from the blades lower surface from the tip surface Body blade longitudinal direction 50 in the direction perpendicular to the [[mu] m] 1.0 inside locations [N / mm ^2] or more 5.0 [N / mm ^2] or less, the elastic blade longitudinal from the tip face 0.4 [N / mm ² ] or more and 0.8 [N / mm ² ] at a location 100 [μm] inside in the direction and 100 [μm] inside in the direction perpendicular to the longitudinal direction of the elastic blade from the lower surface of the blade. The following cleaning blade is used.
According to a ninth aspect of the present invention, a toner image is formed on the image carrier, the toner image is transferred from the image carrier to the transfer body, and then the residual toner on the image carrier is removed by a cleaning blade. In the image forming method to be removed, as the cleaning blade, a strip-shaped elastic blade, a blade lower surface that is a surface facing the surface of a member to be cleaned, and an end surface of the elastic blade in the longitudinal direction of the elastic blade And a surface layer that is harder than the elastic blade and covers the tip ridge line portion that is an angle between the tip end surface and the angle of the tip ridge line portion is not less than 60 [°] and not more than 80 [°]. and, by Vickers indenter load 1 Martens hardness at the elastic blade section perpendicular to the longitudinal direction of the front edge portion near the elastic body blade when measured at [mN] is the angle of the tip ridge portion It is 1.0 [N / mm ² ] or more and 5.0 [N / mm ² ] or less at a position 70 [μm] inside the tip ridge line portion on the center line, and 140 [from the tip ridge line portion on the center line. μm], a cleaning blade having a density of 0.4 [N / mm ² ] or more and 0.8 [N / mm ² ] or less is used.

In the first aspect of the invention, as clarified in a verification experiment to be described later, the Martens hardness of the elastic blade is 50 [μm] inward in the longitudinal direction of the elastic blade from the tip surface and the elastic blade length from the lower surface of the blade. 1.0 [N / mm ² ] or more and 5.0 [N / mm ² ] or less at a location 50 [μm] in the direction orthogonal to the direction, and 100 [N / mm ² ] from the tip surface to the elastic blade longitudinal direction. [mu] m] inside and 100 from the blade lower surface in a direction orthogonal to the elastic blade longitudinal [[mu] m] inside point 0.4 [N / mm ^2] or more 0.8 [N / mm ^2] that less is Thus, even if the surface layer is worn and the tip ridge portion of the elastic blade is exposed, the tip ridge portion can be prevented from being turned up or worn, and the cleaning property can be maintained over a long period of time.
In the invention of claim 2, as clarified in the verification experiment described later, the angle of the tip ridge line portion is 60 [°] or more and 80 [°] or less, and the Martens hardness of the elastic blade is the tip ridge line. It is 1.0 [N / mm ² ] or more and 5.0 [N / mm ² ] or less at a position 70 [μm] inside the tip ridge line portion on the center line of the angle of the portion, and from the tip ridge line portion on the center line Even if the surface layer is worn and the tip ridge portion of the elastic blade is exposed by being 0.4 [N / mm ² ] or more and 0.8 [N / mm ² ] or less at a location inside 140 [μm]. It is possible to suppress turning and wear of the tip ridge line portion, and it is possible to maintain the cleaning property for a long time.
In the invention of claim 8, as clarified in a verification experiment to be described later, as a cleaning blade, a strip-shaped elastic blade, a blade lower surface that is a surface of the elastic blade facing the member to be cleaned, and an elastic body The elastic body of the blade is composed of a surface layer that is harder than the elastic blade and covers the tip ridge line portion that is an angle between the end surface in the longitudinal direction of the blade and the Martens hardness of the elastic blade is the tip surface. From 1.0 [N / mm ² ] to 5.0 [μm] at a location 50 [μm] inward in the longitudinal direction of the elastic blade and 50 [μm] in the direction perpendicular to the longitudinal direction of the elastic blade from the lower surface of the blade. N / mm ² ] or less, and 100 [μm] inside from the tip surface in the longitudinal direction of the elastic blade and 100 in the direction perpendicular to the longitudinal direction of the elastic blade from the blade lower surface. [Μm] By using a cleaning blade that is 0.4 [N / mm ² ] or more and 0.8 [N / mm ² ] or less at the inner part, the surface layer is worn and the tip edge portion of the elastic blade is exposed. Even in this case, the turning and wear of the tip edge line portion can be suppressed, and the occurrence of defective cleaning can be suppressed over a long period of time.
In the invention of claim 9, as clarified in a verification experiment described later, as a cleaning blade, a strip-shaped elastic blade, a blade lower surface that is a surface facing the surface of a member to be cleaned, and an elastic body The elastic body of the blade is composed of a surface layer that is harder than the elastic blade and covers the front edge line that is an angle between the front end face that is the end face in the longitudinal direction of the blade, and the angle of the front edge line is 60 [°] or more. 80 [°] or less, and the Martens hardness of the elastic blade is 1.0 [N / mm ² ] or more at a location 70 [μm] inside the tip ridge line portion on the center line of the angle of the tip ridge line portion. 0.0 [N / mm ² ] or less, and 0.4 [N / mm ² ] or more and 0.8 [N / mm ² ] or less at a position 140 [μm] inside the tip ridge line portion on the center line. Cleaning probe By using the lade, even if the surface layer is worn and the tip ridge line portion of the elastic blade is exposed, the tip ridge line portion can be prevented from turning and wearing, and the occurrence of defective cleaning can be suppressed over a long period of time.

  As described above, according to the first to ninth aspects of the present invention, there is an excellent effect that the turning and wear of the tip ridge line portion can be suppressed and the cleaning property can be maintained over a long period of time.

[Embodiment 1]
A first embodiment in which the present invention is applied to an electrophotographic printer (hereinafter simply referred to as a printer) that is an image forming apparatus will be described below.
FIG. 1 is a schematic configuration diagram illustrating a main part of the printer according to the present embodiment. The printer performs single-color copying, and forms a monochrome image based on image data read by an image reading unit (not shown).

  As shown in FIG. 1, the printer includes a drum-shaped photoconductor 3 as an image carrier. The photosensitive member 3 has a drum shape, but may be a sheet shape or an endless belt shape.

  Around the photosensitive member 3, a charging device 4 as a charging unit, a developing device 5 as a developing unit that converts a latent image into a toner image, a transfer device 7 as a transfer unit that transfers a toner image onto a transfer sheet as a recording medium, Separation claw 8 for separating the transfer paper from the photoreceptor 3, charger 9 before cleaning for aligning the charging polarity of the toner remaining on the photoreceptor 3 after transfer, and toner remaining on the photoreceptor 3 after transfer A cleaning device 6 for cleaning, a lubricant coating device 10, a neutralizing lamp 11 for neutralizing the photosensitive member 3, and the like are arranged.

  The charging device 4 is arranged in a non-contact manner with a predetermined distance from the photoconductor 3, and charges the photoconductor 3 to a predetermined polarity and a predetermined potential. The photosensitive member 3 uniformly charged by the charging device 4 is irradiated with light L based on image data from an exposure device which is a latent image forming unit (not shown) to form an electrostatic latent image.

  The developing device 5 has a developing roller 51 as a developer carrier. A developing bias is applied to the developing roller 51 from a power source (not shown). In the casing of the developing device 5, a supply screw 52 and a stirring screw 53 are provided for stirring the developer contained in the casing while conveying the developer in opposite directions. A doctor 54 for regulating the developer carried on the developing roller 51 is also provided. The toner in the developer stirred and conveyed by the two screws of the supply screw 52 and the stirring screw 53 is charged to a predetermined polarity. The developer is pumped up by the developing roller 51, and the pumped-up developer is regulated by the doctor 54, and the toner adheres to the latent image on the photoconductor 3 in the development area facing the photoconductor 3.

  The transfer device 7 includes a pre-transfer charger 71, a transfer charger 72, and a separation charger 73. Negative corona discharge is performed by the pre-transfer charger 71 to align the polarity of the toner, and then the toner image is transferred onto the transfer paper under corona discharge by the transfer charger 72. The transfer paper is separated from the surface of the photosensitive member 3 by the corona discharge of the separation charger 73 and the separation claw 8.

The cleaning device 6 includes a fur brush 101, a cleaning blade 62, and the like. The cleaning blade 62 is in contact with the photoconductor 3 in the counter direction with respect to the surface movement direction of the photoconductor 3.
The fur brush 101 disturbs the transfer residual toner on the photosensitive member 3 and adheres to the brush to remove a part of the transfer residual toner on the photosensitive member. The toner adhering to the fur brush 101 is flicked by a flicker (not shown), and the repelled toner is conveyed outside the cleaning device 6 by a conveying screw (not shown). In addition, the transfer residual toner on the photosensitive member may be electrostatically removed by applying a bias reverse to the polarity of the pre-cleaning charger 9 to the fur brush 101. Further, the transfer residual toner attached to the fur brush 101 may be electrically removed.

  In addition, the cleaning blade 62 removes the transfer residual toner on the photosensitive member that is easily disturbed by the fur brush 101. Details of the cleaning blade 62 will be described later.

  The lubricant application device 10 includes a solid lubricant 103, a lubricant pressurizing spring 104, and the like. The lubricant application device 10 is also used as the application brush for applying the solid lubricant 103 onto the photosensitive member 3 and also used as the fur brush 101 of the cleaning device 6. Yes. The solid lubricant 103 is held by a bracket (not shown) and is pressed toward the fur brush 101 by a lubricant pressurizing spring 104. Then, the solid lubricant 103 is scraped by the fur brush 101 that rotates in the rotational direction with respect to the rotation direction of the photoconductor 3, and the lubricant is applied onto the photoconductor 3.

  The pre-transfer charger 71, the separation claw 8, and the pre-cleaning charger 9 are arranged as necessary.

As the charging device 4, the pre-transfer charger 71, the transfer charger 72, the separation charger 73, and the pre-cleaning charger 9, known means such as a corotron, a scorotron, and a solid state charger are used.
Among these charging methods, the contact charging method or the non-contact proximity arrangement method is more desirable, and has advantages such as high charging efficiency, a small amount of ozone generation, and miniaturization of the apparatus.

Light sources such as a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), an electroluminescence (EL), etc. All things can be used.
In addition, various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.

  Among these light sources, a light emitting diode and a semiconductor laser have high irradiation energy and have a long wavelength light of 600 to 800 [nm], so that they are used favorably.

Next, an image forming operation in the printer will be described.
When a print execution signal is received from an operation unit (not shown), a predetermined voltage or current is sequentially applied to the charging device 4, the developing roller 51, the pre-transfer charger 71, the transfer charger 72, the separation charger 73, and the pre-cleaning charger 9, respectively. Applied at timing. Similarly, a predetermined voltage or current is sequentially applied to the exposure apparatus and the charge removal lamp 11 at predetermined timing. In synchronism with this, the photosensitive member 3 is rotationally driven in the direction of the arrow in the figure by a photosensitive member driving motor (not shown) as a driving means.

  When the photoconductor 3 rotates in the direction of the arrow in the figure, the surface of the photoconductor is first charged to a predetermined potential by the charging device 4. Then, light L corresponding to the image signal is irradiated onto the photoconductor 3 from an exposure device (not shown), and the portion of the photoconductor 3 irradiated with the light L is neutralized to form an electrostatic latent image.

  The photosensitive member 3 on which the electrostatic latent image is formed is rubbed against the surface of the photosensitive member 3 with a magnetic brush of developer formed on the developing roller 51 at a portion facing the developing device 5. At this time, the negatively charged toner on the developing roller 51 is moved to the electrostatic latent image side by a predetermined developing bias applied to the developing roller 51 to be converted into a toner image (development). Thus, in the present embodiment, the electrostatic latent image formed on the photoreceptor 3 is reversely developed by the developing device 5 with the negatively charged toner. In this embodiment, an example using a non-contact charging roller system of N / P (negative positive: toner adheres to a place where the potential is low) has been described, but the present invention is not limited to this.

  The toner image formed on the photosensitive member 3 passes through a facing portion between the upper registration roller 12 and the lower registration roller 13 from a paper feeding unit (not shown) to a transfer region formed between the photosensitive member 3 and the transfer charger. It is transferred to the transfer paper that is fed. At this time, the transfer paper is supplied in synchronism with the leading edge of the image at the facing portion between the upper registration roller 12 and the lower registration roller 13. In addition, a predetermined transfer bias is applied during transfer onto the transfer paper. The transfer paper onto which the toner image has been transferred is separated from the photosensitive member 3 by the separation claw 8 and the separation charger 73, and is conveyed to a fixing device (not shown) as fixing means. By passing through the fixing device, the toner image is fixed on the transfer paper by the action of heat and pressure, and the transfer paper is discharged out of the apparatus.

  On the other hand, the surface of the photoreceptor 3 after the transfer is subjected to removal of residual toner after the transfer by the cleaning device 6, the lubricant is applied by the lubricant applying device 10, and then the charge is removed by the charge eliminating lamp 11.

  Further, in this printer, the photosensitive member 3, the charging device 4, the developing device 5, the cleaning device 6, the lubricant applying device 10 and the like as process means are housed in the frame 2, and the process cartridge 1 is provided from the main body of the apparatus. It is detachable integrally. In this embodiment, the photosensitive member 3 as the process cartridge 1 and the process means are integrally replaced. However, the photosensitive member 3, the charging device 4, the developing device 5, the cleaning device 6, and the lubricant are used. The structure which replaces | exchanges for a new thing in units like the coating device 10 may be sufficient.

Next, a toner suitable for the printer will be described.
As the toner used in the printer, it is preferable to use a polymerized toner produced by a suspension polymerization method, an emulsion polymerization method, or a dispersion polymerization method, which can easily increase the circularity and reduce the particle size in order to improve the image quality. In particular, it is preferable to use a polymerized toner having a circularity of 0.97 or more and a volume average particle size of 5.5 [μm] or less. By using a material having an average circularity of 0.97 or more and a volume average particle size of 5.5 [μm], a higher resolution image can be formed.

  The “circularity” here is an average circularity measured by a flow type particle image analyzer FPIA-2000 (trade name, manufactured by Toa Medical Electronics Co., Ltd.). Specifically, in 100 to 150 [ml] of water from which impure solids have been removed in advance in a container, 0.1 to 0.5 [ml] of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant, Further, about 0.1 to 0.5 [g] of a measurement sample (toner) is added. Thereafter, the suspension in which the toner is dispersed is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes so that the concentration of the dispersion becomes 3000 to 1 [10,000 / μl]. To measure the shape and distribution of the toner. Based on the measurement result, the outer peripheral length of the actual toner projection shape shown in FIG. 2A is C1, and the projection area is S. The outer circumference of the perfect circle shown in FIG. C2 / C1 was determined when the length was C2, and the average value was defined as the circularity.

  The volume average particle diameter can be determined by a Coulter counter method. Specifically, the toner number distribution and volume distribution data measured by the Coulter Multisizer 2e type (manufactured by Coulter) are sent to a personal computer via an interface (manufactured by Nikkaki Co., Ltd.) for analysis. More specifically, a 1% NaCl aqueous solution using first grade sodium chloride is prepared as an electrolytic solution. Then, 0.1 to 5 [ml] of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant to 100 to 150 [ml] of the electrolytic aqueous solution. Further, 2 to 20 [mg] of toner as a test sample is added thereto, and the dispersion treatment is performed for about 1 to 3 minutes using an ultrasonic disperser. Then, 100 to 200 [ml] of the electrolytic aqueous solution is put into another beaker, and the solution after the dispersion treatment is added to the beaker so as to have a predetermined concentration, and then applied to the Coulter Multisizer 2e type. The aperture is 100 [μm], and the particle size of 50,000 toner particles is measured. As a channel, it is less than 2.00-2.52 [micrometer]; 2.52-less than 3.17 [micrometer]; 3.17-less than 4.00 [micrometer]; 4.00-5.04 [micrometer] Less than 5.04 to 6.35 [μm]; 6.35 to less than 8.00 [μm]; 8.00 to less than 10.08 [μm]; 10.08 to less than 12.70 [μm]; 12.70 to less than 16.00 [μm]; 16.00 to less than 20.20 [μm]; 20.20 to less than 25.40 [μm]; 25.40 to less than 32.00 [μm]; Using 13 channels of 00 to less than 40.30 [μm], toner particles with a particle size of 2.00 [μm] or more and 32.0 [μm] or less are targeted. Then, the volume average particle diameter is calculated based on the relational expression “volume average particle diameter = ΣXfV / ΣfV”. However, X is the representative diameter in each channel, V is the equivalent volume in the representative diameter of each channel, and f is the number of particles in each channel.

  In such a polymerized toner, as described above, if the pulverized toner is removed by the cleaning blade 62 in the same manner as when the pulverized toner is removed from the surface of the photoreceptor 3, the polymerized toner is sufficiently removed from the surface of the photoreceptor 3. Not clean, resulting in poor cleaning. Therefore, when the contact pressure of the cleaning blade 62 to the photosensitive member 3 is increased to improve the cleaning performance, there is a problem that the cleaning blade 62 wears out early. In addition, the frictional force between the cleaning blade 62 and the photosensitive member 3 is increased, and the leading edge portion of the cleaning blade 62 in contact with the photosensitive member 3 is pulled in the moving direction of the photosensitive member 3 so that the leading edge portion is turned. End up. When the tip ridge line portion of the cleaning blade 62 is turned, various problems such as abnormal noise, vibration, and lack of the tip ridge line portion occur.

  Therefore, in the present embodiment, the tip ridge portion of the cleaning blade 62 is subjected to low friction treatment impregnated with at least one selected from an isocyanate compound, a fluorine compound, and a silicone compound, and the tip ridge portion is covered so as to cover the tip ridge portion. A surface layer having a hardness higher than that of the cleaning blade 62 is provided.

  FIG. 3 is a perspective view of the cleaning blade 62, and FIG. 4 is an enlarged configuration diagram of the cleaning blade 62.

  The cleaning blade 62 is composed of a strip-shaped holder 621 made of a rigid material such as metal or hard plastic, and a strip-shaped elastic blade 622. The elastic blade 622 is impregnated with a low friction treatment at the tip ridge. A surface layer 623 is formed so as to cover the tip ridge line portion 62c in the vicinity of the tip ridge line portion 62c of the cleaning blade 62 and the blade lower surface 62b.

  The elastic blade 622 is fixed to one end side of the holder 621 with an adhesive or the like, and the other end side of the holder 621 is supported by the case of the cleaning device 6.

  As the elastic body blade and 622, a highly repulsive elastic body is preferable so that it can follow the eccentricity of the photosensitive body 3 and minute waviness on the surface of the photosensitive body, and urethane rubber which is a rubber containing a urethane group is suitable. is there. In particular, urethane rubber having a hardness at 25 ° C. of 70 to 75 degrees (JIS A) and a rebound resilience of 30 to 68 [%] is preferable. When the hardness of the urethane rubber exceeds 75 degrees, the flexibility becomes poor. For example, when the holder 621 is attached with a slight inclination, the contact pressure between the one end side and the other end side in the axial direction of the cleaning blade 62 is reduced. Different so-called uneven contact is likely to occur, and it is difficult to obtain a uniform contact pressure in the axial direction. As a result, there is a possibility that the cleaning property is deteriorated. On the other hand, when the hardness is less than 70 degrees, the cleaning blade 62 is warped when the contact pressure is set to be high so that even the polymerized toner can be cleaned, and the tip ridge line portion 62c of the cleaning blade 62 is lifted, and the cleaning is performed. A so-called anti-hit phenomenon in which the blade lower surface 62b of the blade 62 abuts against the photosensitive member 3 occurs. When the stomach contact phenomenon occurs, the contact area between the cleaning blade 62 and the surface of the photosensitive member increases rapidly, so that the contact pressure is reduced even if the cleaning blade 62 is pressed with a large force, and the cleaning performance is deteriorated. End up.

  Moreover, the fact is that there is almost no urethane rubber having a rebound resilience exceeding 68 [%], and since it is not a general-purpose product, there is a risk that the cost will increase. On the other hand, when the resilience elastic modulus exceeds 68 [%], an abnormal noise such as a high-pitched blade is likely to occur when the cleaning blade 62 is turned over. On the other hand, if the rebound resilience is less than 30 [%], the followability to the eccentricity of the photosensitive member 3 and the minute waviness of the photosensitive member surface is deteriorated, and the cleaning property may be deteriorated.

  Thus, good cleaning properties can be obtained by using urethane rubber having a hardness of 70 to 75 degrees (JIS A) at 25 [° C.] and a rebound resilience of 30 to 68 [%] as urethane rubber. it can.

Here, the Martens hardness in a cross section perpendicular to the longitudinal direction of the elastic blade of the leading edge portion 62c in the elastic blade 622 is 50 [μm] inward in the longitudinal direction of the elastic blade from the tip surface 62a as shown in FIG. And it is 1.0-5.0 [N / mm < ² >] in the location inside 50 [[mu] m] in the direction orthogonal to the elastic blade longitudinal direction from the blade lower surface 62b, and the elastic blade longitudinal direction from the tip surface 62a. 100 [μm] to the inner side and 0.4 to 0.8 [N / mm ² ] at a position 100 [μm] inside in the direction orthogonal to the longitudinal direction of the elastic blade from the blade lower surface 62b. Thus, as clarified in a verification experiment to be described later, the turning and wear of the tip ridge line portion 62c of the elastic blade 622 can be suppressed, and there is no abnormal noise such as chattering. The packaging of can be well maintained. By controlling the hardness inside the tip of the elastic blade 622 (in the vicinity of the tip ridge line portion) to the Martens hardness within the above range, moderate mobility is maintained in the vicinity of the tip ridge line portion of the elastic blade 622. It is considered that turning of the front edge line portion 62c, wear, and abnormal noise can be avoided in a well-balanced manner. Further, this hardness is preferably a local state inside the tip of the elastic blade 622 (near the tip ridge), particularly at locations inside the tip surface 62a from 100 [μm] and the blade lower surface 62b to 100 [μm]. The state which is the hardness of urethane rubber itself is good.

  This hardness changes due to the modification of the urethane rubber itself by the impregnation action, and is also affected by the formation of the surface layer. Therefore, it is necessary to adjust each effect.

  The impregnation treatment of the tip ridge line portion of the elastic blade 622 can be performed by impregnating at least one selected from an isocyanate compound, a fluorine compound, and a silicone compound by spray coating, dip coating, or the like. This results in two reforming effects: hardness change and low friction, and the friction coefficient should be 0.5 or less. Thereby, the frictional force between the edge portion of the elastic blade 622 exposed due to wear over time and the photosensitive member 3 can be weakened, and deformation of the exposed portion in the direction of movement of the photosensitive member surface can also be suppressed. .

  The surface layer 623 covers the tip edge line portion 62c of the cleaning blade 62 by spray coating or dip coating. The surface layer 623 is preferably covered with a member having a hardness higher than that of the elastic blade 622. By using a member having a hardness higher than that of the elastic blade 622, the cleaning blade 62 is less likely to be scraped off by the photosensitive member 3 than the elastic blade 622, and compared with a member that makes the elastic blade 622 contact the surface of the photosensitive member. The wear resistance of can be improved. Further, since the surface layer 623 is hard and rigid, it is difficult to be deformed, and it is possible to suppress the turning of the tip ridge line portion 62 c of the cleaning blade 62.

  The material of the surface layer 623 is preferably a resin, and more preferably an ultraviolet curable resin. By using the ultraviolet curable resin, the surface layer 623 having the desired hardness can be obtained simply by irradiating the resin adhered to the tip ridge line portion 62c of the cleaning blade 62 with ultraviolet rays, and the cleaning blade 62 is manufactured at low cost. be able to.

  As the ultraviolet curable resin, it is preferable to use a monomer having a molecular weight of 300 to 1500 per functional group. When the molecular weight exceeds 1500, the surface layer 623 becomes too fragile, the tip ridge line portion 62c of the cleaning blade 62 turns over, and the tip surface wear as shown in FIG. It cannot be held. On the other hand, when the molecular weight is less than 300, the surface layer 623 becomes too rigid. If the surface layer 623 is too rigid, the wear resistance performance of the surface layer 623 is reduced and chatter noise is likely to occur.

  In addition, it is preferable to form a surface layer on the tip surface 62a and the blade lower surface 62b up to a position 50 [μm] away from the tip ridge line portion 62c that may come into contact with the photosensitive member 3. As a result, the surface of the tip ridge line portion 62c is scraped, the elastic blade 622 and the photoconductor 3 are in direct contact, and the tip ridge line portion 62c is turned up, and a place away from the tip ridge line portion 62c of the tip face 62a by several [μm]. Even when it comes into contact with the photosensitive member 3, the surface layer 623 is formed there, so that local wear of the front end face 62a is suppressed. Accordingly, it is possible to suppress the lack of the leading edge portion 62c of the cleaning blade 62 due to local wear of the leading edge surface 62a. Further, the contact pressure of the cleaning blade 62 becomes higher than necessary due to the mounting error of the photosensitive member 3 or the mounting error of the cleaning blade, and the cleaning blade 62 bends more than necessary, so that the tip ridge line portion 62c of the blade lower surface 62b is bent. Even if a part separated by several [μm] is in contact with the photoreceptor 3, the surface layer 623 is formed there, so that local abrasion of the blade lower surface 62b can be suppressed.

  The layer thickness of the surface layer 623 is preferably 1 to 50 [μm]. When the layer thickness is 1 [μm] or less, the rigidity of the surface layer becomes weak, and the tip ridge line portion 62c of the cleaning blade 62 is likely to be turned over. On the other hand, if the layer thickness exceeds 50 [μm], toner slip-through increases and cleaning failure is likely to occur. This is because the surface layer 623 is formed by adhering a liquid material as in spray coating or dip coating, and the tip ridge line portion 62c is difficult to form a film due to the surface tension. For this reason, the layer thickness of the surface layer 623 increases as the distance from the tip ridge line portion 62c increases. When the layer thickness exceeds 50 [μm], the difference between the layer thickness of the tip ridge line portion 62c and the layer thickness at a position away from the tip ridge line portion 62c increases, and the angle of the tip ridge line portion 62c of the cleaning blade 62 becomes an obtuse angle. turn into. When the angle of the leading edge line part 62c becomes an obtuse angle, the gap X (see FIG. 4) on the upstream side of the contact part formed by the leading edge surface 62a and the photoreceptor 3 is narrower than when the leading edge line part 62c is a right angle. Become. For this reason, when toner accumulates in the gap by a cleaning operation over a long period of time, the toner in the blocked gap X has no escape, so the toner in the gap X is gradually pushed out to the downstream side of the photoreceptor 3. A cleaning failure occurs.

Next, a verification experiment conducted by the applicants will be described.
Durability tests were performed by changing the material of the elastic blade 622, the impregnation treatment method, and the material of the surface layer 623, respectively.

[Elastic blade]
As the elastic blade 622, five urethane rubbers having the following physical properties at 25 [° C.] were prepared.
Urethane rubber 1: Hardness 70 degrees, rebound resilience 50 [%] (Toyo Tire & Rubber)
Urethane rubber 2: hardness 72 degrees, rebound resilience 31 [%] (manufactured by Toyo Tire & Rubber)
Urethane rubber 3: Hardness 71 degrees, rebound resilience 18 [%] (manufactured by Toyo Tire & Rubber)
Urethane rubber 4: Hardness 77 degrees, rebound resilience 27 [%] (manufactured by Syndtech)
Urethane rubber 5: hardness 70 degrees, rebound resilience 68 [%] (manufactured by Syndtech)

  The hardness of urethane rubber was measured according to JIS K6253 using a durometer manufactured by Shimadzu Corporation. The sample was a stack of approximately 2 [mm] sheets so that the thickness was 6 [mm] or more.

  The resilience of urethane rubber is No. manufactured by Toyo Seiki Seisakusho. The measurement was performed according to JIS K6255 using a 221 regilynester. The sample was a stack of about 2 [mm] sheets so that the thickness was 4 [mm] or more.

[Impregnating agent]
As the impregnating agent, the following were used.
(Impregnating agent 1)
Isocyanate compound: Nippon Polyurethane MR-100 10 parts 2-butanone 90 parts

(Impregnating agent 2)
Isocyanate compound: Nippon Polyurethane MR-100 10 parts Silicone resin: NOF Modiper FS-700 2 parts 2-butanone 88 parts

(Impregnating agent 3)
Isocyanate compound: Kanto Chemical MDI 5 parts 2-butanone 95 parts

(Impregnating agent 4)
Isocyanate compound: Kanto Kagaku MDI 5 parts Silicone resin: NOF Modiper FS-700 2 parts 2-butanone 93 parts

[Surface layer]
The following were used as the surface layer.

(Surface layer 1)
Urethane acrylate oligomer 1: Negami Kogyo UN-904 0.5 part Urethane acrylate oligomer 2: Negami Kogyo UN-2700 19.5 parts Polymerization initiator: Ciba Specialty Chemicals Irgacure 184 1 part Solvent: 2-butanone 79 parts Coating film Hardness: Pencil hardness 2H
Friction coefficient: 0.6

(Surface layer 2)
Urethane acrylate oligomer 1: Negami Kogyo UN-904 5 parts Urethane acrylate oligomer 2: Negami Kogyo UN-2700 15 parts Polymerization initiator: Ciba Specialty Chemicals Irgacure 184 1 part Solvent: 2-butanone 79 parts Coating film hardness: Pencil hardness 3H
Friction coefficient: 0.5

(Surface layer 3)
Urethane acrylate oligomer 1: Negami Kogyo UN-904 0.5 part Urethane acrylate oligomer 2: Negami Kogyo UN-2700 19.5 parts Low friction coefficient additive: Chisso Petrochemical Copolymer A1 5 parts Polymerization initiator: Ciba Specialty Chemicals Irgacure 184 1 part Solvent: 74 parts of 2-butanone Coating film hardness: Pencil hardness H
Friction coefficient: 0.1

(Surface layer 4)
Urethane acrylate oligomer 1: Negami Kogyo UN-3320HA 5 parts Urethane acrylate oligomer 2: Negami Kogyo UN-2700 15 parts Low friction coefficient additive: Chisso Petrochemical Copolymer A1 2 parts Polymerization initiator: Ciba Specialty Chemicals Irgacure 184 1 part Solvent: 2-butanone 77 parts Coating film hardness: pencil hardness 2H
Friction coefficient: 0.15

(Surface layer 5)
Urethane acrylate oligomer 1: Negami Kogyo UN-904 20 parts Polymerization initiator: Ciba Specialty Chemicals Irgacure 184 1 part Solvent: 2-butanone 79 parts Coating film hardness: pencil hardness 9H
Friction coefficient: 0.45

  The copolymer A1 added as the additive for reducing the friction coefficient of the surface layer is obtained by copolymerizing the compound (a-1) shown in the following chemical formula 1 and the compound (a-2) shown in the chemical formula 1 below. And a copolymer having an acryloyl group (a-3 shown in Chemical Formula 1 below) in the side chain.

  The copolymer (A1) obtained by GPC (gel permeation chromatography) analysis had a weight average molecular weight of 37,000 (polystyrene conversion) and a molecular weight distribution index (Mw / Mn) of 1.9. Further, the content ratio (weight ratio) of the compound (a-1) and the compound (a-2) in the copolymer (A1) determined by 1H-NMR measurement is as follows: Compound (a-1): Compound (a -2) = 1: 1.73.

The pencil hardness of the surface layer was measured according to JIS K5600-5-4 using a pencil scratch tester KTVF-2380 manufactured by Cortec Corporation. The sample was obtained by spraying the surface layer material about 10 [μm] on a 50 [mm] × 50 [mm] glass plate.
As the friction coefficient of the surface layer, the maximum static friction coefficient was measured using a tribogear muse 94i manufactured by Shinto Kagaku. The sample was obtained by spraying the coating material on a glass plate of 50 [mm] × 50 [mm] by about 10 [μm].

Further, the Martens hardness in a cross section perpendicular to the longitudinal direction of the elastic blade near the tip ridge line portion of the elastic blade 622 is a sample obtained by cutting the cross section with a trimming razor for SEM sample preparation made by Nisshin EM, and is shown in FIG. As shown in the figure, a point 50 [μm] inward in the longitudinal direction of the elastic blade from the tip surface 62a and 50 [μm] in the direction perpendicular to the longitudinal direction of the elastic blade from the blade lower surface 62b, and the tip surface 62a The Fisherscope HM2000 manufactured by Fischer Instruments is used in two places, 100 [μm] inside in the longitudinal direction of the elastic blade and 100 [μm] inside in the direction orthogonal to the longitudinal direction of the elastic blade from the blade lower surface 62b. Used, the Vickers indenter was measured at 1 mN with a weight of 30 seconds and a pulling force of 30 seconds.
In addition, the Martens hardness before the impregnation process of the urethane rubbers 1 to 5 used as the elastic body blade (the place where the impregnation process is not performed) is 0.4 to 0.8 [N / mm ² ]. Met.

Next, the configuration of the image forming apparatus for which the verification experiment has been performed will be described.
A rectangular elastic blade having a thickness of 2 [mm] is prepared using any one of the urethane rubbers 1 to 5, and the elastic blade is immersed in any of the impregnating agents 1 to 4 for a predetermined time. Air-dry for a minute and then spray coating to form any one of the surface layers 1 to 4. Specifically, for each elastic blade made of urethane rubber that has been appropriately impregnated, if necessary, at a spray gun moving speed of 10 [mm / s] from two directions of the blade lower surface and the tip surface. Overcoat was applied so as to have a layer thickness, and after touch-drying for 3 minutes, ultraviolet exposure (140 [W / cm] × 5 [m / min] × 5 passes) was performed. However, the lower surface of the blade was regulated so as to form a surface layer with a width of 3 mm at the tip by masking tape.

  The elastic blade on which this surface layer was formed was fixed with an adhesive to a sheet metal holder that can be mounted on the Ricoh color composite machine imagio Neo C455, to obtain a prototype cleaning blade. This was attached to a Ricoh color composite machine image Neo Neo C455 (same configuration as FIG. 1), and image forming apparatuses of Examples 1 to 7 and Comparative Examples 1 to 5 were produced. The cleaning blade was attached so that the linear pressure was 20 [g / cm] and the cleaning angle was 79 [°].

In the verification experiment, a toner prepared by a polymerization method was used. The physical properties of the toner are as follows.
Toner base: circularity 0.98, average particle size 4.9 [μm]
External additive: 1.5 parts of small particle size silica (Clariant H2000)
0.5 parts small particle size titanium oxide (Taika MT-150AI)
1.0 parts of large particle size silica (UFP-30H manufactured by Denki Kagaku Kogyo)

  The verification experiment was performed at 50,000 sheets (A4 landscape) with 3 prints / job for an evaluation environment: 20 [° C.] / 65 [% RH], and a paper feeding condition: image area ratio of 5 [%]. And the following items were evaluated.

[Evaluation item]
Occurrence of cleaning failure: Existence (image area ratio 5% chart output visual observation)
Blade edge wear width: Wear width seen from the blade lower side as shown in FIG.

  The result of the verification experiment of the cleaning blade of Examples 1 to 7 and Comparative Examples 1 to 5 is shown below. In addition, the layer thickness of the surface layer was measured with a cross section of an elastic blade separately coated in the same manner using a Keyence microscope VHX-100. The sample was a cross-section cut using a trimming razor for SEM sample preparation manufactured by Nisshin EM.

  In addition, the friction coefficient at the tip ridge line portion of the elastic blade was measured using a Shinto Kagaku Co., Ltd. friction wear tester (blade holder mounted). Specifically, a “pseudo-photosensitive member” in which a film having the same component as that of the photosensitive member surface layer is formed on a glass plate is subjected to the same contact conditions as described above (angle: 79 °, linear pressure: 20 [g / cm]), and the glass plate was moved to measure the dynamic friction coefficient.

Example 1
Base urethane rubber: Urethane rubber 3
Impregnating agent: Impregnating agent 2
Impregnation time: 180 seconds Surface layer: Surface layer 2
Surface layer thickness at 50 [μm] from edge: blade lower surface 1 [μm], tip surface 12 [μm]
Tip internal hardness at 50 [μm] from the edge: 1.3 [N / mm ² ]
Tip internal hardness at 100 [μm] from edge: 0.7 [N / mm ² ]
Tip friction coefficient: 0.1
Blade edge wear width: 8 [μm]
Occurrence of cleaning failure: None Occurrence of abnormal noise: None

(Example 2)
Base urethane rubber: Urethane rubber 1
Impregnating agent: Impregnating agent 1
Impregnation time: 5 seconds Surface layer: Surface layer 1
Surface layer thickness at 50 [μm] from edge: blade lower surface 0 [μm], tip surface 1 [μm]
Tip internal hardness at 50 [μm] from edge: 1.0 [N / mm ² ]
Tip internal hardness at 100 [μm] from the edge: 0.4 [N / mm ² ]
Tip friction coefficient: 0.5
Blade edge wear width: 12 [μm]
Occurrence of cleaning failure: None Occurrence of abnormal noise: None

(Example 3)
Base urethane rubber: Urethane rubber 2
Impregnating agent: Impregnating agent 1
Impregnation time: 600 seconds Surface layer: Surface layer 4
Surface layer thickness at 50 [μm] from edge: blade lower surface 0 [μm], tip surface 12 [μm]
Tip internal hardness at 50 [μm] from edge: 1.4 [N / mm ² ]
Tip internal hardness at 100 [μm] from edge: 0.5 [N / mm ² ]
Tip friction coefficient: 0.2
Blade edge wear width: 10 [μm]
Occurrence of cleaning failure: None Occurrence of abnormal noise: None

Example 4
Base urethane rubber: Urethane rubber 3
Impregnating agent: Impregnating agent 3
Impregnation time: 180 seconds Surface layer: Surface layer 3
Surface layer thickness at 50 [μm] from edge: blade lower surface 5 [μm], tip surface 12 [μm]
End internal hardness at 50 [μm] from edge: 1.8 [N / mm ² ]
Tip internal hardness at 100 [μm] from edge: 0.7 [N / mm ² ]
Tip friction coefficient: 0.1
Blade edge wear width: 9 [μm]
Occurrence of cleaning failure: None Occurrence of abnormal noise: None

(Example 5)
Base urethane rubber: Urethane rubber 5
Impregnating agent: Impregnating agent 3
Impregnation time: 600 seconds Surface layer: Surface layer 2
Surface layer thickness at 50 [μm] from edge: blade lower surface 1 [μm], tip surface 5 [μm]
Tip internal hardness at 50 [μm] from edge: 2.1 [N / mm ² ]
Tip internal hardness at 100 [μm] from the edge: 0.4 [N / mm ² ]
Tip friction coefficient: 0.2
Blade edge wear width: 14 [μm]
Occurrence of cleaning failure: None Occurrence of abnormal noise: None

(Example 6)
Base urethane rubber: Urethane rubber 3
Impregnating agent: Impregnating agent 2
Impregnation time: 600 seconds Surface layer: Surface layer 3
Surface layer thickness at 50 [μm] from edge: blade lower surface 5 [μm], tip surface 5 [μm]
Tip internal hardness at 50 [μm] from edge: 2.4 [N / mm ² ]
Tip internal hardness at 100 [μm] from edge: 0.7 [N / mm ² ]
Tip friction coefficient: 0.1
Blade edge wear width: 5 [μm]
Occurrence of cleaning failure: None Occurrence of abnormal noise: None

(Example 7)
Base urethane rubber: Urethane rubber 4
Impregnating agent: impregnating agent 4
Impregnation time: 180 seconds Surface layer: Surface layer 5
Surface layer thickness at 50 [μm] from the edge: blade lower surface 30 [μm], tip surface 50 [μm]
Tip internal hardness at 50 [μm] from edge: 5.0 [N / mm ² ]
Tip internal hardness at 100 [μm] from the edge: 0.8 [N / mm ² ]
Tip friction coefficient: 0.2
Blade edge wear width: 18 [μm]
Occurrence of cleaning failure: None Occurrence of abnormal noise: None

(Comparative Example 1)
Base urethane rubber: Urethane rubber 1
Impregnating agent: None Surface layer: Surface layer 1
Surface layer thickness at 50 [μm] from edge: blade lower surface 10 [μm], tip surface 20 [μm]
Tip internal hardness at 50 [μm] from edge: 0.8 [N / mm ² ]
Tip internal hardness at 100 [μm] from edge: 0.7 [N / mm ² ]
Tip friction coefficient: 0.6
Blade edge wear width: 22 [μm]
Occurrence of poor cleaning: Two belt-like cleaning defects Abnormal noise: None

(Comparative Example 2)
Base urethane rubber: Urethane rubber 2
Impregnating agent: None Surface layer: Surface layer 3
Surface layer thickness at 50 [μm] from edge: blade lower surface 5 [μm], tip surface 10 [μm]
Tip internal hardness at 50 [μm] from edge: 0.7 [N / mm ² ]
Tip internal hardness at 100 [μm] from edge: 0.7 [N / mm ² ]
Tip friction coefficient: 0.3
Blade edge wear width: 25 [μm]
Occurrence of poor cleaning: Two belt-like cleaning defects Abnormal noise: None

(Comparative Example 3)
Base urethane rubber: Urethane rubber 3
Impregnating agent: impregnating agent 4
Impregnation time: 600 seconds Surface layer: Surface layer 5
Surface layer thickness at 50 [μm] from the edge: blade lower surface 50 [μm], tip surface 80 [μm]
Tip internal hardness at 50 [μm] from edge: 4.5 [N / mm ² ]
Tip internal hardness at 100 [μm] from edge: 1.5 [N / mm ² ]
Tip friction coefficient: 0.4
Blade edge wear width: 30 [μm]
Occurrence of cleaning failure: 3 streaky cleaning failures Abnormal noise occurrence: chattering

(Comparative Example 4)
Base urethane rubber: Urethane rubber 1
Impregnating agent: Impregnating agent 1
Impregnation time: 600 seconds Surface layer: Surface layer 5
Surface layer thickness at 50 [μm] from the edge: blade lower surface 50 [μm], tip surface 50 [μm]
Tip internal hardness at 50 [μm] from edge: 5.0 [N / mm ² ]
Tip internal hardness at 100 [μm] from edge: 1.8 [N / mm ² ]
Tip friction coefficient: 0.6
Blade edge wear width: 30 [μm]
Occurrence of cleaning failure: 4 streaky cleaning failures Occurrence of abnormal noise: chattering

(Comparative Example 5)
Base urethane rubber: Urethane rubber 4
Impregnating agent: impregnating agent 4
Impregnation time: 900 seconds Surface layer: Surface layer 5
Surface layer thickness at 50 [μm] from edge: blade lower surface 80 [μm], tip surface 100 [μm]
End internal hardness at 50 [μm] from the edge: 7.0 [N / mm ² ]
Tip internal hardness at 100 [μm] from edge: 2.1 [N / mm ² ]
Tip friction coefficient: 0.4
Blade edge wear width: 31 [μm]
Occurrence of cleaning failure: 2 streaky cleaning failures Abnormal noise occurrence: chattering

  Table 1 above summarizes the results of verification experiments of Examples 1 to 7 and Comparative Examples 1 to 5.

In Examples 1 to 7, the Martens hardness inside the tip of the elastic blade (near the tip ridge) is 50 [μm] from the tip surface within the cross section perpendicular to the longitudinal direction of the elastic blade and from the blade lower surface. It is 1.0 to 5.0 [N / mm ² ] at 50 [μm], and 0.4 to 0.8 [N] at 100 [μm] from the tip surface and 100 [μm] from the blade lower surface. / Mm ² ], that is, the state where the inside of the tip of the elastic blade is locally hardened, and as described above, the turning and wear of the tip ridge line portion of the elastic blade can be suppressed. Thus, it is considered that the conventional chip face wear is suppressed and good cleaning performance can be maintained. In addition, since the tip edge line part modification process including the low friction process was performed and the friction coefficient of the tip edge line part was controlled to 0.5 or less, it was considered that the generation of abnormal noise over time could be avoided. It is done. Furthermore, the frictional force generated between the surface of the photoreceptor and the tip ridge line portion can be reduced, the turning of the tip ridge line portion can be further suppressed, and the abrasion of the elastic blade can be further suppressed. It is thought.

  On the other hand, in Comparative Example 1 and Comparative Example 2, since the impregnation treatment was not performed, the hardness inside the tip of the elastic blade near the tip ridge line portion was low, and the tip ridge line portion was turned up, and a surface layer was formed. However, since the hardness of the inside of the tip of the elastic blade is low, the elastic blade is deformed, and as a result, it is considered that the tip side face wear and poor cleaning have occurred. Further, in Comparative Example 3 and Comparative Example 4, since the increase in the hardness inside the tip of the elastic blade extends further to the inside, the mobility of the elastic blade is suppressed, and the energy generated by the friction with the photoconductor It is considered that the increase in the amount of wear and the generation of abnormal noise occurred due to the accelerated wear. In Comparative Example 5, the hardness inside the tip of the elastic blade was higher than in Comparative Example 3 and Comparative Example 4 and the like, and as in Comparative Example 3 and Comparative Example 4 and the like, an increase in wear amount and generation of abnormal noise occurred. Conceivable. Further, in Comparative Example 3 and Comparative Example 4, since the surface layer is thick, the hardness of the surface layer affects the movement of the elastic blade, and the friction coefficient at the tip ridge is low. It is thought that the generation of abnormal noise could not be avoided.

  The present embodiment is an example of a so-called monochrome image forming apparatus, but may be a color image forming apparatus. Hereinafter, a specific example in which the feature points of the present embodiment are applied to a color image forming apparatus will be described.

  FIG. 7 is a diagram showing an example in which the present invention is applied to a color printer which is a so-called tandem type color image forming apparatus.

  In FIG. 7, reference numeral (3C, 3M, 3Y, 3K) denotes a drum-shaped photoconductor, and the photoconductors 3C, 3M, 3Y, 3K rotate in the direction of the arrow in the figure and are charged around at least in the order of rotation. Devices 4C, 4M, 4Y, 4K, developing devices 5C, 5M, 5Y, 5K, and cleaning devices 6C, 6M, 6Y, 6K are arranged.

  Laser light LC, LM, LY, LK from an exposure device (not shown) is irradiated from the back side of the photoreceptor between the charging devices 4C, 4M, 4Y, 4K and the developing devices 5C, 5M, 5Y, 5K. Electrostatic latent images are formed on 3C, 3M, 3Y, and 3K. Then, four process cartridges 1C, 1M, 1Y, and 1K centering on such photoreceptors 3C, 3M, 3Y, and 3K are juxtaposed along a transfer conveyance belt 14 that is a transfer material conveyance unit. The transfer / conveying belt 14 contacts the photosensitive members 3C, 3M, 3Y, and 3K between the developing devices 5C, 5M, 5Y, and 5K of the process cartridges 1C, 1M, 1Y, and 1K and the cleaning devices 6C, 6M, 6Y, and 6K. In addition, transfer devices 7C, 7M, 7Y, and 7K for applying a transfer bias are disposed on the surface (back surface) of the transfer and transport belt 14 that contacts the back side of the photoconductor. Each of the process cartridges 1C, 1M, 1Y, and 1K has a different toner color inside the developing device, and the others have the same configuration.

  In the color printer having the configuration shown in FIG. 7, the image forming operation is performed as follows. First, in each of the process cartridges 1C, 1M, 1Y, and 1K, the photoconductors 3C, 3M, 3Y, and 3K are charged by the charging devices 4C, 4M, 4Y, and 4K that rotate in the direction of the arrow (the direction around the photoconductor). Next, an electrostatic latent image corresponding to each color image to be created is formed by laser light LC, LM, LY, and LK by an exposure device (not shown) arranged inside the photoconductor.

  Next, the latent image is developed by the developing devices 5C, 5M, 5Y, and 5K to form a toner image. The developing devices 5C, 5M, 5Y, and 5K are developing devices that perform development with toners of C (cyan), M (magenta), Y (yellow), and K (black), respectively, and the four photosensitive members 3C, 3M, and 3Y. , 3K toner images of each color are superimposed on the transfer paper.

  The transfer paper P is sent out from the tray by the paper supply roller 15, temporarily stopped by the upper registration roller 12 and the lower registration roller 13, and sent to the transfer conveyance belt 14 in synchronization with the image formation on the photosensitive member. The transfer paper P held on the transfer conveyance belt 14 is conveyed, and the toner images of the respective colors are transferred at the contact positions (transfer portions) with the photoconductors 3C, 3M, 3Y, 3K.

  The toner image on the photoconductor is transferred onto the transfer paper P by an electric field formed by the potential difference between the transfer bias applied to the transfer devices 7C, 7M, 7Y, and 7K and the photoconductors 3C, 3M, 3Y, and 3K. The Then, the transfer paper P on which the four color toner images are passed through the four transfer portions is conveyed to the fixing device 16 where the toner is fixed and discharged to a paper discharge portion (not shown). Further, the residual toner that is not transferred by the transfer unit and remains on the photosensitive members 3C, 3M, 3Y, and 3K is collected by the cleaning devices 6C, 6M, 6Y, and 6K. In the example of FIG. 7, the image forming elements are arranged in the order of C (cyan), M (magenta), Y (yellow), and K (black) from the upstream side to the downstream side in the transfer paper conveyance direction. However, it is not limited to this order, and the color order is arbitrarily set.

  Further, when a black-only document is created, it is particularly effective to use the present invention to provide a mechanism for stopping the process cartridges 1C, 1M, and 1Y other than black. Further, although the charging device is in contact with the photosensitive member in FIG. 7, by providing an appropriate gap (about 10 to 200 [μm]) between the two, the wear amount of both can be reduced and the charging member can be reduced. The toner filming can be reduced and can be used satisfactorily.

The cleaning devices 6C, 6M, 6Y, and 6K of the process cartridges 1C, 1M, 1Y, and 1K each include a cleaning blade, and the tip ridge line portion of the cleaning blade has a Martens hardness in a cross section perpendicular to the longitudinal direction of the blade member. Is 1.0 to 5.0 [N / mm ² ] within 50 [μm] from the tip surface and 50 [μm] from the blade bottom surface, 100 [μm] from the tip surface and 100 [μm] from the blade bottom surface. within the [mu] m], it is 0.4~0.8 [N / mm ^2].

  Since this color printer has the above-described configuration, even if the linear pressure of the cleaning blade is increased so that the polymerized toner can be cleaned, the tip ridge line portion of the cleaning blade does not turn, and good cleaning properties are achieved. Can be maintained over time. Further, the progress of abrasion of the photoreceptor is suppressed, and a good image can be maintained over a long period.

[Embodiment 2]
A second embodiment in which the present invention is applied to an electrophotographic printer (hereinafter simply referred to as a printer) that is an image forming apparatus will be described below. The basic configuration of the printer according to the present embodiment is substantially the same as that of the printer according to the first embodiment, and a description thereof will be omitted.

  In the present embodiment, the cleaning device 6 is provided with a cleaning blade as shown in FIGS. That is, the tip of the cleaning blade 62 has an acute angle, and the tip ridge portion 62c is subjected to a low friction treatment impregnated with at least one selected from an isocyanate compound, a fluorine compound, and a silicone compound, and the tip ridge portion 62c is covered. A surface layer 623 having higher hardness than the cleaning blade 62 is provided.

  FIG. 8 is a perspective view of the cleaning blade 62, and FIG. 9 is an enlarged configuration diagram of the cleaning blade 62.

  The cleaning blade 62 is composed of a strip-shaped holder 621 made of a rigid material such as metal or hard plastic, and a strip-shaped elastic blade 622. The elastic blade 622 has an acute angle at the tip, and a tip ridge line portion. The surface layer 623 is formed so as to cover the tip ridge line portion 62c in the vicinity of the entire tip surface 62a of the cleaning blade 62 and the tip ridge line portion 62c of the blade lower surface 62b.

  The elastic blade 622 is fixed to one end side of the holder 621 with an adhesive or the like, and the other end side of the holder 621 is supported by the case of the cleaning device 6.

  As the elastic body blade and 622, a highly repulsive elastic body is preferable so that it can follow the eccentricity of the photosensitive body 3 and minute waviness on the surface of the photosensitive body, and urethane rubber which is a rubber containing a urethane group is suitable. is there. In particular, urethane rubber having a hardness at 25 ° C. of 70 to 75 degrees (JIS A) and a rebound resilience of 30 to 68 [%] is preferable. When the hardness of the urethane rubber exceeds 75 degrees, the flexibility becomes poor. For example, when the holder 621 is attached with a slight inclination, the contact pressure between the one end side and the other end side in the axial direction of the cleaning blade 62 is reduced. Different so-called uneven contact is likely to occur, and it is difficult to obtain a uniform contact pressure in the axial direction. As a result, there is a possibility that the cleaning property is deteriorated. On the other hand, when the hardness is less than 70 degrees, the cleaning blade 62 is warped when the contact pressure is set to be high so that even the polymerized toner can be cleaned, and the tip ridge line portion 62c of the cleaning blade 62 is lifted, and the cleaning is performed. A so-called anti-hit phenomenon in which the blade lower surface 62b of the blade 62 abuts against the photosensitive member 3 occurs. When the stomach contact phenomenon occurs, the contact area between the cleaning blade 62 and the surface of the photosensitive member increases rapidly, so that the contact pressure is reduced even if the cleaning blade 62 is pressed with a large force, and the cleaning performance is deteriorated. End up.

  Moreover, the fact is that there is almost no urethane rubber having a rebound resilience exceeding 68 [%], and since it is not a general-purpose product, there is a risk that the cost will increase. On the other hand, when the resilience elastic modulus exceeds 68 [%], an abnormal noise such as a high-pitched blade is likely to occur when the cleaning blade 62 is turned over. On the other hand, if the rebound resilience is less than 30 [%], the followability to the eccentricity of the photosensitive member 3 and the minute waviness of the photosensitive member surface is deteriorated, and the cleaning property may be deteriorated.

  Thus, good cleaning properties can be obtained by using urethane rubber having a hardness of 70 to 75 degrees (JIS A) at 25 [° C.] and a rebound resilience of 30 to 68 [%] as urethane rubber. it can.

Here, the tip ridge line portion 62c of the elastic blade has an angle between the blade lower surface 62b of the tip ridge line portion 62c and the tip surface 62a of 60 [°] to 80 [°], and the elasticity of the tip ridge line portion 62c. The Martens hardness in a cross section perpendicular to the longitudinal direction of the body blade is 1. on the inner side of the tip ridge line portion 62c to 70 [μm] on the center line of the angle formed by the blade lower surface 62b and the tip surface 62a as shown in FIG. 0-5.0 was [N / mm ^2], by such a 0.4~0.8 [N / mm ^2] on the inside of the 140 [[mu] m] from the front edge portion 62c at the center line As clarified in a verification experiment to be described later, turning-up and wear of the tip ridge line portion 62c of the elastic blade 622 can be suppressed, and no abnormal noise such as chatter can be generated, and the cleaning performance can be maintained satisfactorily. This is presumably because the tip ridge line portion 62c is first formed into an acute angle to prevent the tip ridge line portion from being rounded when the tip ridge line portion is worn, and to prevent the toner from slipping. By controlling the hardness inside the tip of the elastic blade 622 (in the vicinity of the tip ridge line portion) to the Martens hardness within the above range, moderate mobility is maintained in the vicinity of the tip ridge line portion of the elastic blade 622. It is considered that turning of the ridge line portion 62c, wear and generation of abnormal noise can be avoided in a balanced manner. Furthermore, this hardness is preferably a local state inside the tip of the elastic blade 622 (near the tip ridge), and particularly from the tip ridges 62c to 140 on the center line of the angle formed by the blade lower surface 62b and the tip 62a. Inside [μm], the state of the hardness of the urethane rubber itself is good.

  Note that this hardness changes due to the modification of the urethane rubber itself by the impregnation action, and is also affected by the formation of the surface layer 623. Therefore, it is necessary to adjust each effect.

  The impregnation treatment to the tip ridge line portion 62c of the elastic blade 622 can be performed by impregnating at least one selected from an isocyanate compound, a fluorine compound, and a silicone compound by spray coating, dip coating, or the like. This results in two reforming effects: hardness change and low friction, and the friction coefficient should be 0.5 or less. Thereby, the frictional force between the edge portion of the elastic blade 622 exposed due to wear over time and the photosensitive member 3 can be weakened, and deformation of the exposed portion in the direction of movement of the photosensitive member surface can also be suppressed. .

  The surface layer 623 covers the tip edge line portion 62c of the cleaning blade 62 by spray coating or dip coating. The surface layer 623 is preferably covered with a member having a hardness higher than that of the elastic blade 622. By using a member having a hardness higher than that of the elastic blade 622, the cleaning blade 62 is less likely to be scraped off by the photosensitive member 3 than the elastic blade 622, and compared with a member that makes the elastic blade 622 contact the surface of the photosensitive member. The wear resistance of can be improved. Further, since the surface layer 623 is hard and rigid, it is difficult to be deformed, and it is possible to suppress the turning of the tip ridge line portion 62 c of the cleaning blade 62.

  The material of the surface layer 623 is preferably a resin, and more preferably an ultraviolet curable resin. By using the ultraviolet curable resin, the surface layer 623 having the desired hardness can be obtained simply by irradiating the resin adhered to the tip ridge line portion 62c of the cleaning blade 62 with ultraviolet rays, and the cleaning blade 62 is manufactured at low cost. be able to.

  As the ultraviolet curable resin, it is preferable to use a monomer having a molecular weight of 300 to 1500 per functional group. When the molecular weight exceeds 1500, the surface layer 623 becomes too fragile, the tip ridge line portion 62c of the cleaning blade 62 turns over, and the tip surface wear as shown in FIG. It cannot be held. On the other hand, when the molecular weight is less than 300, the surface layer 623 becomes too rigid. If the surface layer 623 is too rigid, the wear resistance performance of the surface layer 623 is reduced and chatter noise is likely to occur.

  In addition, it is preferable to form a surface layer on the tip surface 62a and the blade lower surface 62b up to a position 50 [μm] away from the tip ridge line portion 62c that may come into contact with the photosensitive member 3. As a result, the surface of the tip ridge line portion 62c is scraped, the elastic blade 622 and the photoconductor 3 are in direct contact, and the tip ridge line portion 62c is turned up, and a place away from the tip ridge line portion 62c of the tip face 62a by several [μm]. Even when it comes into contact with the photosensitive member 3, the surface layer 623 is formed there, so that local wear of the front end face 62a is suppressed. Accordingly, it is possible to suppress the lack of the leading edge portion 62c of the cleaning blade 62 due to local wear of the leading edge surface 62a.

  Further, the contact pressure of the cleaning blade 62 becomes higher than necessary due to the mounting error of the photosensitive member 3 or the mounting error of the cleaning blade, and the cleaning blade 62 bends more than necessary, so that the tip ridge line portion 62c of the blade lower surface 62b is bent. Even if a part separated by several [μm] is in contact with the photoreceptor 3, the surface layer 623 is formed there, so that local abrasion of the blade lower surface 62b can be suppressed.

  The layer thickness of the surface layer 623 is preferably 1 to 50 [μm]. When the layer thickness is 1 [μm] or less, the rigidity of the surface layer becomes weak, and the tip ridge line portion 62c of the cleaning blade 62 is likely to be turned over. On the other hand, if the layer thickness exceeds 50 [μm], toner slip-through increases and cleaning failure is likely to occur. This is because the surface layer 623 is formed by adhering a liquid material as in spray coating or dip coating, and therefore the tip ridge line portion 62c is less likely to form a film due to surface tension. For this reason, the layer thickness of the surface layer 623 increases as the distance from the tip ridge line portion 62c increases. When the layer thickness exceeds 50 [μm], the difference between the layer thickness of the tip ridge line portion 62c and the layer thickness at a position away from the tip ridge line portion 62c increases, and the angle of the tip ridge line portion 62c of the cleaning blade 62 becomes an obtuse angle. turn into. When the angle of the tip ridge line portion 62c becomes an obtuse angle, the gap X (see FIG. 9) on the upstream side of the contact portion formed by the tip surface 62a and the photosensitive member 3 is narrower than when the tip ridge line portion 62c is a right angle. Become. For this reason, when toner accumulates in the gap by a cleaning operation over a long period of time, the toner in the blocked gap X has no escape, so the toner in the gap X is gradually pushed out to the downstream side of the photoreceptor 3. A cleaning failure occurs.

Next, verification experiments conducted by the inventors will be described.
Durability tests were conducted by changing the material of the elastic blade 622, the angle formed by the blade lower surface 62b and the tip surface 62a of the tip edge line portion 62c, the impregnation treatment method, and the material of the surface layer 623, respectively.

[Elastic blade]
As the elastic blade 622, five urethane rubbers having the following physical properties at 25 [° C.] were prepared.
Urethane rubber 1: Hardness 70 degrees, rebound resilience 50 [%] (Toyo Tire & Rubber)
Urethane rubber 2: hardness 72 degrees, rebound resilience 31 [%] (manufactured by Toyo Tire & Rubber)
Urethane rubber 3: Hardness 71 degrees, rebound resilience 18 [%] (manufactured by Toyo Tire & Rubber)
Urethane rubber 4: Hardness 77 degrees, rebound resilience 27 [%] (manufactured by Syndtech)
Urethane rubber 5: hardness 70 degrees, rebound resilience 68 [%] (manufactured by Syndtech)

  The hardness of urethane rubber was measured according to JIS K6253 using a durometer manufactured by Shimadzu Corporation. The sample was a stack of approximately 2 [mm] sheets so that the thickness was 6 [mm] or more.

  The resilience of urethane rubber is No. manufactured by Toyo Seiki Seisakusho. The measurement was performed according to JIS K6255 using a 221 regilynester. The sample was a stack of about 2 [mm] sheets so that the thickness was 4 [mm] or more.

[Impregnating agent]
As the impregnating agent, the following were used.
(Impregnating agent 1)
Isocyanate compound: Nippon Polyurethane MR-100 10 parts 2-butanone 90 parts

(Impregnating agent 2)
Isocyanate compound: Nippon Polyurethane MR-100 10 parts Silicone resin: NOF Modiper FS-700 2 parts 2-butanone 88 parts

(Impregnating agent 3)
Isocyanate compound: Kanto Chemical MDI 5 parts 2-butanone 95 parts

(Impregnating agent 4)
Isocyanate compound: Kanto Kagaku MDI 5 parts Silicone resin: NOF Modiper FS-700 2 parts 2-butanone 93 parts

[Surface layer]
The following were used as the surface layer.
(Surface layer 1)
Urethane acrylate oligomer 1: Negami Kogyo UN-904 0.5 part Urethane acrylate oligomer 2: Negami Kogyo UN-2700 19.5 parts Polymerization initiator: Ciba Specialty Chemicals Irgacure 184 1 part Solvent: 2-butanone 79 parts Coating film Hardness: Pencil hardness 2H
Friction coefficient: 0.6

(Surface layer 2)
Urethane acrylate oligomer 1: Negami Kogyo UN-904 5 parts Urethane acrylate oligomer 2: Negami Kogyo UN-2700 15 parts Polymerization initiator: Ciba Specialty Chemicals Irgacure 184 1 part Solvent: 2-butanone 79 parts Coating film hardness: Pencil hardness 3H
Friction coefficient: 0.5

(Surface layer 3)
Urethane acrylate oligomer 1: Negami Kogyo UN-904 0.5 part Urethane acrylate oligomer 2: Negami Kogyo UN-2700 19.5 parts Low friction coefficient additive: Chisso Petrochemical Copolymer A1 5 parts Polymerization initiator: Ciba Specialty Chemicals Irgacure 184 1 part Solvent: 74 parts of 2-butanone Coating film hardness: Pencil hardness H
Friction coefficient: 0.1

(Surface layer 4)
Urethane acrylate oligomer 1: Negami Kogyo UN-3320HA 5 parts Urethane acrylate oligomer 2: Negami Kogyo UN-2700 15 parts Low friction coefficient additive: Chisso Petrochemical Copolymer A1 2 parts Polymerization initiator: Ciba Specialty Chemicals Irgacure 184 1 part Solvent: 2-butanone 77 parts Coating film hardness: pencil hardness 2H
Friction coefficient: 0.15

(Surface layer 5)
Urethane acrylate oligomer 1: Negami Kogyo UN-904 20 parts Polymerization initiator: Ciba Specialty Chemicals Irgacure 184 1 part Solvent: 2-butanone 79 parts Coating film hardness: pencil hardness 9H
Friction coefficient: 0.45

  The copolymer A1 added as a low friction coefficient additive for the surface layer 4 is a copolymer of the compound (a-1) shown in the above chemical formula 1 and the compound (a-2) shown in the chemical formula 1 above. And a copolymer having an acryloyl group (a-3 shown in Chemical Formula 1 above) in the side chain.

  The copolymer (A1) obtained by GPC (gel permeation chromatography) analysis had a weight average molecular weight of 37,000 (polystyrene conversion) and a molecular weight distribution index (Mw / Mn) of 1.9. Further, the content ratio (weight ratio) of the compound (a-1) and the compound (a-2) in the copolymer (A1) determined by 1H-NMR measurement is as follows: Compound (a-1): Compound (a -2) = 1: 1.73.

  The pencil hardness of the surface layer was measured according to JIS K5600-5-4 using a pencil scratch tester KTVF-2380 manufactured by Cortec Corporation. The sample was obtained by spraying the surface layer material about 10 [μm] on a 50 [mm] × 50 [mm] glass plate.

  As the friction coefficient of the surface layer, the maximum static friction coefficient was measured using a tribogear muse 94i manufactured by Shinto Kagaku. The sample was obtained by spraying the coating material on a glass plate of 50 [mm] × 50 [mm] by about 10 [μm].

Further, the Martens hardness in the cross section perpendicular to the blade member longitudinal direction of the blade tip ridge line portion is an angle formed by cutting the cross section with a trimming razor for SEM sample preparation made by Nisshin EM, and the angle formed between the blade lower surface 62b and the tip surface. On the center line, the Fischer Instruments HM2000 manufactured by Fischer Instruments was used at two locations inside the 70 [μm] and 140 [μm] from the edge of the tip, and the Vickers indenter was loaded at 1 [mN] for 30 seconds, Measurement was performed with a 30-second pull.
In addition, the Martens hardness before the impregnation process of the urethane rubbers 1 to 5 used as the elastic body blade (the place where the impregnation process is not performed) is 0.4 to 0.8 [N / mm ² ]. Met.

Next, the configuration of the image forming apparatus for which the verification experiment has been performed will be described.
A rectangular elastic blade having a thickness of 2 [mm] is prepared using any one of the urethane rubbers 1 to 5, and the elastic blade is immersed in any of the impregnating agents 1 to 4 for a predetermined time. Air-dry for a minute and then spray coating to form any one of the surface layers 1 to 4. Specifically, for each elastic blade made of urethane rubber appropriately impregnated, predetermined at a spray gun moving speed of 10 [mm / s] from the two directions of the blade lower surface 62b and the tip surface as necessary. The film was overcoated so as to have a layer thickness of 3 mm, and after touch-drying for 3 minutes, ultraviolet exposure (140 [W / cm] × 5 [m / min] × 5 passes) was performed. However, the blade lower surface 62b was regulated by a masking tape so that a surface layer was formed with a width of 3 [mm] at the tip.

  The elastic blade on which this surface layer was formed was fixed with an adhesive to a sheet metal holder that can be mounted on the Ricoh color composite machine imagio Neo C455, to obtain a prototype cleaning blade. This was attached to a Ricoh color composite machine image Neo Neo C455 (same configuration as in FIG. 1), and image forming apparatuses of Examples 1 to 7 and Comparative Examples 1 to 5 were produced. The cleaning blade was mounted so that the linear pressure was 20 [g / cm] and the cleaning angle was 79 [°] (however, the difference from 90 [°] was added when the blade edge was an acute angle). .

In the verification experiment, a toner prepared by a polymerization method was used. The physical properties of the toner are as follows.
Toner base: circularity 0.98, average particle size 4.9 [μm]
External additive: 1.5 parts of small particle size silica (Clariant H2000)
0.5 parts small particle size titanium oxide (Taika MT-150AI)
1.0 parts of large particle size silica (UFP-30H manufactured by Denki Kagaku Kogyo)

  The verification experiment was performed at 50,000 sheets (A4 landscape) with 3 prints / job for an evaluation environment: 20 [° C.] / 65 [% RH], and a paper feeding condition: image area ratio of 5 [%]. And the following items were evaluated.

[Evaluation item]
Occurrence of defective cleaning: Presence / absence (image area ratio 5 [%] chart output visual observation)
Blade edge wear width: Wear width seen from the bottom side of the blade

  The results of verification experiments on the cleaning blades of Examples 8 to 13 and Comparative Examples 6 to 9 are shown below. In addition, the layer thickness of the surface layer was measured with a cross section of an elastic blade separately coated in the same manner using a Keyence microscope VHX-100. The sample was a cross-section cut using a trimming razor for SEM sample preparation manufactured by Nisshin EM.

  The coefficient of friction of the elastic blade tip ridge was measured using a Shinto Kagaku Co., Ltd. friction wear tester (blade holder mounted). Specifically, a “pseudo-photosensitive member” in which a film having the same component as the surface layer of the photosensitive member is formed on a glass plate is subjected to the same contact conditions as described above (angle: 79 [°], linear pressure: 20 [ g / cm]), the glass plate was moved, and the dynamic friction coefficient at that time was measured.

(Example 8)
Base urethane rubber: Urethane rubber 3
Angle between the blade bottom surface and the tip surface at the tip ridge line: 80 [°]
Impregnating agent: Impregnating agent 3
Impregnation time: 180 seconds Surface layer: Surface layer 3
Surface layer thickness at 50 [μm] from edge: blade lower surface 5 [μm], tip surface 10 [μm]
Tip internal hardness at 70 [μm] from edge: 1.9 [N / mm ² ]
Tip internal hardness at 140 [μm] from edge: 0.7 [N / mm ² ]
Tip friction coefficient: 0.1
Blade edge wear width: 8 [μm]
Occurrence of cleaning failure: None Occurrence of abnormal noise: None

Example 9
Base urethane rubber: Urethane rubber 1
Angle between the blade lower surface and the tip surface at the tip ridge line part: 70 [°]
Impregnating agent: Impregnating agent 1
Impregnation time: 5 seconds Surface layer: Surface layer 1
Surface layer thickness at 50 [μm] from the edge: blade lower surface 0 [μm], tip surface 2 [μm]
Tip internal hardness at 70 [μm] from edge: 1.0 [N / mm ² ]
Tip internal hardness at 140 [μm] from edge: 0.4 [N / mm ² ]
Tip friction coefficient: 0.5
Blade edge wear width: 11 [μm]
Occurrence of cleaning failure: None Occurrence of abnormal noise: None

(Example 10)
Base urethane rubber: Urethane rubber 3
Angle between the blade bottom surface and the tip surface at the tip ridge line: 80 [°]
Impregnating agent: Impregnating agent 2
Impregnation time: 180 seconds Surface layer: Surface layer 2
Surface layer thickness at 50 [μm] from edge: blade lower surface 2 [μm], tip surface 15 [μm]
End internal hardness at 70 [μm] from edge: 1.5 [N / mm ² ]
Tip internal hardness at 140 [μm] from edge: 0.7 [N / mm ² ]
Tip friction coefficient: 0.1
Blade edge wear width: 7 [μm]
Occurrence of cleaning failure: None Occurrence of abnormal noise: None

(Example 11)
Base urethane rubber: Urethane rubber 2
Angle between the blade lower surface and the tip surface of the tip ridge line part: 60 [°]
Impregnating agent: Impregnating agent 1
Impregnation time: 600 seconds Surface layer: Surface layer 4
Surface layer thickness at 50 [μm] from edge: blade lower surface 0 [μm], tip surface 10 [μm]
Tip internal hardness at 70 [μm] from edge: 1.6 [N / mm ² ]
Tip internal hardness at 140 [μm] from edge: 0.5 [N / mm ² ]
Tip friction coefficient: 0.2
Blade edge wear width: 11 [μm]
Occurrence of cleaning failure: None Occurrence of abnormal noise: None

(Example 12)
Base urethane rubber: Urethane rubber 4
Angle between the blade bottom surface and the tip surface at the tip ridge line: 75 [°]
Impregnating agent: impregnating agent 4
Impregnation time: 180 seconds Surface layer: Surface layer 5
Surface layer thickness at 50 [μm] from edge: blade lower surface 35 [μm], tip surface 50 [μm]
Tip internal hardness at 70 [μm] from edge: 5.0 [N / mm ² ]
Tip internal hardness at 140 [μm] from the edge: 0.8 [N / mm ² ]
Tip friction coefficient: 0.2
Blade edge wear width: 16 [μm]
Occurrence of cleaning failure: None Occurrence of abnormal noise: None

(Example 13)
Base urethane rubber: Urethane rubber 5
Angle between the blade bottom surface and the tip surface at the tip ridge line: 75 [°]
Impregnating agent: Impregnating agent 3
Impregnation time: 600 seconds Surface layer: Surface layer 2
Surface layer thickness at 50 [μm] from edge: blade lower surface 2 [μm], tip surface 5 [μm]
End internal hardness at 70 [μm] from edge: 2.3 [N / mm ² ]
Tip internal hardness at 140 [μm] from edge: 0.4 [N / mm ² ]
Tip friction coefficient: 0.2
Blade edge wear width: 12 [μm]
Occurrence of cleaning failure: None Occurrence of abnormal noise: None

(Comparative Example 6)
Base urethane rubber: Urethane rubber 2
Angle between the blade lower surface and the tip surface at the tip ridge line part: 55 [°]
Impregnating agent: None Surface layer: Surface layer 3
Surface layer thickness at 50 [μm] from edge: blade lower surface 5 [μm], tip surface 10 [μm]
Tip internal hardness at 70 [μm] from edge: 0.7 [N / mm ² ]
Tip internal hardness at 140 [μm] from edge: 0.7 [N / mm ² ]
Tip friction coefficient: 0.3
Blade edge wear width: 25 [μm]
Occurrence of cleaning failure: 4 belt cleaning failures Abnormal noise generation: None

(Comparative Example 7)
Base urethane rubber: Urethane rubber 1
Angle between the blade lower surface and the tip surface at the tip ridge line: 90 [°]
Impregnating agent: Impregnating agent 1
Impregnation time: 600 seconds Surface layer: Surface layer 5
Surface layer thickness at 50 [μm] from the edge: blade lower surface 50 [μm], tip surface 50 [μm]
Tip internal hardness at 70 [μm] from edge: 5.0 [N / mm ² ]
Tip internal hardness at 140 [μm] from edge: 1.8 [N / mm ² ]
Tip friction coefficient: 0.6
Blade edge wear width: 30 [μm]
Occurrence of cleaning failure: 4 streaky cleaning failures Occurrence of abnormal noise: chattering

(Comparative Example 8)
Base urethane rubber: Urethane rubber 1
Angle between the blade lower surface and the tip surface at the tip ridge line: 85 [°]
Impregnating agent: None Surface layer: Surface layer 1
Surface layer thickness at 50 [μm] from edge: blade lower surface 10 [μm], tip surface 20 [μm]
Tip internal hardness at 70 [μm] from the edge: 0.8 [N / mm ² ]
Tip internal hardness at 140 [μm] from edge: 0.7 [N / mm ² ]
Tip friction coefficient: 0.6
Blade edge wear width: 22 [μm]
Occurrence of poor cleaning: Two belt-like cleaning defects Abnormal noise: None

(Comparative Example 9)
Base urethane rubber: Urethane rubber 3
Angle between the blade bottom surface and the tip surface at the tip ridge line: 80 [°]
Impregnating agent: impregnating agent 4
Impregnation time: 600 seconds Surface layer: Surface layer 5
Surface layer thickness at 50 [μm] from the edge: blade lower surface 50 [μm], tip surface 80 [μm]
Tip internal hardness at 70 [μm] from the edge: 4.5 [N / mm ² ]
Tip internal hardness at 140 [μm] from edge: 1.5 [N / mm ² ]
Tip friction coefficient: 0.4
Blade edge wear width: 30 [μm]
Occurrence of cleaning failure: 3 belt-like cleaning failures Abnormal noise occurrence: chattering

Table 2 above summarizes the results of verification experiments of Examples 8 to 13 and Comparative Examples 6 to 9.
In Examples 8 to 13, the angle between the blade lower surface and the tip surface of the tip ridge line portion is 60 [°] to 80 [°], and the inside of the tip of the elastic blade (near the tip ridge line portion) The Martens hardness is 1.0 to 5.0 [N / mm ² ] within 70 [μm] from the tip ridge line portion on the center line of the angle of the tip ridge line portion in the cross section perpendicular to the longitudinal direction of the elastic blade. Yes, 0.4 to 0.8 [N / mm ² ] within 140 [μm] from the tip ridge line portion on the center line, that is, the tip ridge line portion has an acute angle and the tip inside is locally Since it is in a hard state, curling of the tip ridge line and tip wear caused by the tip are suppressed, and rounding due to wear of the tip ridge is small and the amount of wear is small, thus maintaining good cleaning performance. It seems that we were able to In addition, the tip of the elastic blade including the low friction treatment is modified on the tip ridge line and inside the tip, and the friction coefficient of the tip ridge line is controlled to 0.5 or less. It is thought that it was possible to avoid. Furthermore, the frictional force generated between the surface of the photoconductor and the tip ridge line portion can be reduced, the turning of the tip ridge line portion can be further suppressed, and the wear of the tip ridge line portion of the elastic blade can be further suppressed. It is thought that it was possible.

  On the other hand, in Comparative Example 6 and Comparative Example 8, since the impregnation treatment is not performed, the hardness inside the tip of the elastic blade (near the tip ridge line) is low and the tip ridge line is in contact with an acute angle. If the pressure is insufficient and the edge of the tip edge is not acute, the tip end surface wears out, and it is considered that any of them has caused a cleaning failure.

  In Comparative Example 7 and Comparative Example 9, since the increase in the hardness is further extended to the inside, the mobility of the elastic blade is suppressed, and the energy generated by the friction with the photoconductor cannot be dissipated and the wear is promoted. It is thought that the increase in the amount of wear and the generation of abnormal noise were caused. Furthermore, in Comparative Example 9, since the thickness of the surface layer is large, the hardness of the surface layer affects the movement of the elastic blade, and the generation of abnormal noise is suppressed even when the friction coefficient of the tip ridge is low. It is thought that it could not be avoided.

  So far, an example of a so-called monochrome image forming apparatus has been described, but a color image forming apparatus may be used. Hereinafter, the case where the feature point of this embodiment is applied to a color image forming apparatus will be described. The basic configuration of this color image forming apparatus is the same as that of the color printer which is the tandem type color image forming apparatus of Embodiment 1 shown in FIG.

The following cleaning blades are provided in the cleaning devices 6C, 6M, 6Y, and 6K of the process cartridges 1C, 1M, 1Y, and 1K included in the color printer of the present embodiment as illustrated in FIG. That is, the cleaning blade has a Martens hardness in a cross section perpendicular to the longitudinal direction of the blade member having an angle between the blade lower surface and the tip surface of the tip ridge line portion of 60 [°] to 80 [°]. 0 to the inside of 70 [μm] from the tip ridge line portion and 1.0 to 5.0 [N / mm ² ] from the tip ridge line portion and 140 [μm] from the tip ridge line portion on the center line of the angle formed by the tip surface. Cleaning blades of 4 to 0.8 [N / mm ² ] are provided in the cleaning devices 6C, 6M, 6Y, and 6K.

  Since the color printer according to the present embodiment has the above-described configuration, even if the linear pressure of the cleaning blade is increased so that the polymerized toner can be cleaned, the tip ridge line portion of the cleaning blade is not turned up and is good. Cleanability can be maintained over time. Further, the progress of abrasion of the photoreceptor is suppressed, and a good image can be maintained over a long period.

As described above, according to the present embodiment, in the cleaning blade 62 that contacts the surface of the photosensitive member 3 that is a member to be cleaned and removes toner that is powder from the surface of the photosensitive member, the strip-shaped elastic blade 622; The surface of the photoreceptor 3, which is the angle between the blade lower surface 62 b that is the surface facing the photoreceptor surface of the elastic blade 622 and the tip surface 62 a that is the end surface of the elastic blade 622 in the longitudinal direction of the elastic blade, The elastic body blade 622 that is harder than the elastic body blade 622 and covers the contacting front end ridge line portion 62c, and the elastic body blade longitudinal length in the vicinity of the front edge ridge line portion of the elastic body blade 622 when measured with a load of 1 [mN] by a Vickers indenter. Martens hardness at a cross section perpendicular to the direction, the elastic blade longitudinally 50 from the distal end surface 62a [[mu] m] inside and elastic the blade lower surface 62b Blade longitudinally in a direction perpendicular to 50 [[mu] m] inside point 1.0 [N / mm ^2] or more 5.0 [N / mm ^2] or less, the elastic blade longitudinally from the distal end face 62a [N / mm ² ] to 0.8 [N / mm ² ] at a location 100 [μm] inside and 100 [μm] inside in the direction perpendicular to the longitudinal direction of the elastic blade from the blade lower surface 62b. It is as follows. Thereby, as clarified by the above-described verification result, it is possible to prevent the tip ridge line portion 62c from being turned over even if the surface layer 623 is worn and the tip ridge line portion 62c of the elastic blade 622 is exposed. Cleanability can be maintained.
Further, according to the present embodiment, in the cleaning blade 62 that contacts the surface of the photosensitive member 3 that is a member to be cleaned and removes toner that is powder from the surface of the photosensitive member, the strip-shaped elastic blade 622; The surface of the photoreceptor 3, which is the angle between the blade lower surface 62 b that is the surface facing the photoreceptor surface of the elastic blade 622 and the tip surface 62 a that is the end surface of the elastic blade 622 in the longitudinal direction of the elastic blade, It is composed of a surface layer 623 that is harder than the elastic blade 622 and covers the contacting tip ridge line portion 62c, and the angle of the tip ridge line portion 62c is not less than 60 [°] and not more than 80 [°], and a load of 1 by the Vickers indenter Martens hardness at the elastic blade section perpendicular to the longitudinal direction of the front edge portion near the elastic blade 622 when measured at [mN] is the angle of the tip edge 62c It is 1.0 [N / mm ² ] or more and 5.0 [N / mm ² ] or less at a point 70 [μm] inside the tip ridge line portion 62c on the center line, and the tip ridge line portions 62c to 140 [140 [ [mu] m] is 0.4 [N / mm ^2] or more 0.8 [N / mm ^2] or less inside the location. Thereby, as clarified by the above-described verification result, it is possible to prevent the tip ridge line portion 62c from being turned over even if the surface layer 623 is worn and the tip ridge line portion 62c of the elastic blade 622 is exposed. Cleanability can be maintained.
In addition, according to the present embodiment, the elastic blade 622 is subjected to a low friction treatment in which the tip ridge portion 62c is impregnated with at least one selected from an isocyanate compound, a fluorine compound, and a silicone compound, and the friction coefficient of the tip ridge portion 62c. Is 0.5 or less. As a result, the frictional force generated between the surface of the photoreceptor 3 and the leading edge line portion 62c can be reduced, curling of the leading edge line portion can be suppressed, and wear of the elastic blade 622 can be suppressed. Can do.
Further, according to the present embodiment, the surface layer 623 is preferably made of an ultraviolet curable resin, and the layer thickness on the front end surface side of the surface layer 623 is preferably 1 [μm] or more and 50 [μm] or less. That is, as described above, when the layer thickness is less than 1 [μm], the rigidity of the surface layer 623 becomes weak, the tip ridge line portion 62c of the cleaning blade 62 is easily turned, and the layer thickness is 50 [μm]. This is because toner slipping increases and cleaning failure tends to occur. Further, since the surface layer 623 is made of an ultraviolet curable resin, the surface layer 623 having a desired hardness can be obtained simply by irradiating the resin adhered to the tip ridge line portion 62c of the cleaning blade 62 with an ultraviolet ray. 62 can be manufactured at low cost.
Further, according to the present embodiment, the elastic blade 622 is made of rubber containing a urethane group, so that the elastic blade 622 is deformed flexibly even if the photosensitive member 3 is eccentric, and a predetermined contact is obtained. The contact pressure can be maintained, and good cleaning properties can be maintained.
In addition, according to the present embodiment, high-quality images can be maintained over time by removing the transfer residual toner on the surface of the photoconductor with the above-described cleaning blade 62 in the image forming apparatus.
In addition, according to the present embodiment, the above-described cleaning blade 62 is integrally configured as the process cartridge 1, so that a process cartridge with good cleaning properties can be provided.
Further, according to the present embodiment, a toner image is formed on the photosensitive member 3 that is an image carrier, and after the toner image is transferred from the photosensitive member 3 to the transfer member, the remaining on the photosensitive member 3 is cleaned by the cleaning blade. In the image forming method for removing toner, as a cleaning blade, a strip-shaped elastic blade 622, a blade lower surface 62b that is a surface facing the photosensitive member surface of the elastic blade 622, and an elastic blade longitudinal direction of the elastic blade 622 are used. And a surface layer 623 that is harder than the elastic blade 622 and covers the tip ridge line portion 62c that is in contact with the surface of the photoreceptor 3, which is an angle between the tip surface 62a that is the end surface of the photosensitive member 3, and the load 1 is applied by the Vickers indenter. Martens hardness at the elastic blade section perpendicular to the longitudinal direction of the front edge portion near the elastic blade 622 when measured at [mN] is the tip Elastic blade longitudinally 50 from 62a [[mu] m] 50 from the inside and the blade lower surface 62b in a direction perpendicular to the elastic blade longitudinal [[mu] m] 1.0 inside locations [N / mm ^2] or more 5. 0 [N / mm ² ] or less, 0 at a location 100 [μm] inside from the tip surface in the elastic blade longitudinal direction and 100 [μm] inside from the blade lower surface in a direction perpendicular to the elastic blade longitudinal direction. By using the cleaning blade 62 that is not less than 4 [N / mm ² ] and not more than 0.8 [N / mm ² ], the surface layer 623 is worn and the elastic blade 622 is clarified in the verification experiment described above. Even if the tip ridge line portion 62c is exposed, the tip ridge line portion 62c can be prevented from being turned over, and the occurrence of poor cleaning can be suppressed over a long period of time.
Further, according to the present embodiment, a toner image is formed on the photosensitive member 3 that is an image carrier, and after the toner image is transferred from the photosensitive member 3 to the transfer member, the remaining on the photosensitive member 3 is cleaned by the cleaning blade. In the image forming method for removing toner, as a cleaning blade, a strip-shaped elastic blade 622, a blade lower surface 62b that is a surface facing the photosensitive member surface of the elastic blade 622, and an elastic blade longitudinal direction of the elastic blade 622 are used. A surface layer 623 that is harder than the elastic blade 622 and covers the tip ridge line portion 62c that is in contact with the surface of the photoconductor 3, which is an angle between the tip surface 62a that is the end face of the tip ridge line 62c. The angle is 60 [°] or more and 80 [°] or less, and near the tip ridge line portion of the elastic blade 622 when measured with a load of 1 [mN] by a Vickers indenter Martens hardness at the elastic blade section perpendicular to the longitudinal direction of the near is 70 from the leading edge 62c on the center line of the angle of the tip edge 62c [[mu] m] inside point 1.0 [N / ^mm 2] It is 5.0 [N / mm ² ] or less and 0.4 [N / mm ² ] or more and 0.8 [N / mm ² ] at a location 140 [μm] inside the tip ridge line portion 62c on the center line. By using the cleaning blade 62 which is described below, the tip ridge line portion 62c is turned up even when the surface layer 623 is worn and the tip ridge line portion 62c of the elastic blade 622 is exposed, as clarified in the verification experiment described above. The occurrence of poor cleaning can be suppressed over a long period of time.

1 is a schematic configuration diagram of a printer according to an embodiment of the present invention. (A) And (b) is explanatory drawing for demonstrating the measuring method of circularity. FIG. 3 is a perspective view of the cleaning blade according to the first embodiment. FIG. 3 is an enlarged configuration diagram of the cleaning blade according to the first embodiment. FIG. 3 is a schematic diagram illustrating a Martens hardness measurement location inside the tip of the elastic blade in the first embodiment. The schematic diagram which showed the measurement location of the abrasion width | variety of an elastic-body blade. 1 is a main part configuration diagram of a tandem full-color image forming apparatus. FIG. 6 is a perspective view of a cleaning blade according to a second embodiment. FIG. 4 is an enlarged configuration diagram of a cleaning blade according to a second embodiment. The schematic diagram which showed the Martens hardness measurement location inside the front-end | tip of the elastic body blade in Embodiment 2. FIG. (A) The figure which shows the state in which the cleaning blade front-end ridgeline part was turned up. (B) The figure explaining the local abrasion of the front end surface of a cleaning blade. (C) The figure which shows the state which the front-end ridgeline part of the cleaning blade missing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Process cartridge 2 Frame 3 Photoconductor 4 Charging device 5 Developing device 6 Cleaning device 7 Transfer device 8 Separation claw 9 Charger before cleaning 10 Lubricant application device 11 Static elimination lamp 12 Upper registration roller 13 Lower registration roller 14 Transfer conveyance belt 15 Supply Paper roller 16 Fixing device 23 Image carrier 51 Developing roller 52 Supply screw 53 Stirring screw 54 Doctor 62 Cleaning blade 62a Tip surface 62b Blade bottom surface 62c Tip edge line portion 71 Pre-transfer charger 72 Transfer charger 73 Separation charger 101 Fur brush 103 Solid lubricant 104 Lubricant pressurizing spring 262 Cleaning blade 262a Tip surface 262b Blade lower surface 262c Tip ridge 621 Holder 622 Elastic blade 623 Surface layer

Claims (9)

In the cleaning blade that contacts the surface of the member to be cleaned and removes the powder from the surface of the member to be cleaned,
A strip-shaped elastic blade,
The elastic body that covers a tip ridge line portion that is an angle between a blade lower surface that is a surface facing the surface of a member to be cleaned of the elastic blade and a tip surface that is an end surface of the elastic blade in the longitudinal direction of the elastic blade. Consists of a harder surface layer than the blade,
The Martens hardness in a cross section perpendicular to the longitudinal direction of the elastic blade near the tip edge portion of the elastic blade when measured with a load of 1 [mN] by a Vickers indenter is 50 in the longitudinal direction of the elastic blade from the tip surface. [Μm] 1.0 [N / mm ² ] or more and 5.0 [N / mm ² ] or less at a location 50 [μm] inside in the direction perpendicular to the longitudinal direction of the elastic blade from the lower surface of the blade There is 0.4 [N / mm ² ] at a location 100 [μm] inward in the longitudinal direction of the elastic blade from the tip surface and 100 [μm] in the direction perpendicular to the longitudinal direction of the elastic blade from the lower surface of the blade. The cleaning blade is characterized in that it is 0.8 [N / mm ² ] or less. In the cleaning blade that contacts the surface of the member to be cleaned and removes the powder from the surface of the member to be cleaned,
A strip-shaped elastic blade,
The elastic body that covers a tip ridge line portion that is an angle between a blade lower surface that is a surface facing the surface of a member to be cleaned of the elastic blade and a tip surface that is an end surface of the elastic blade in the longitudinal direction of the elastic blade. Consists of a harder surface layer than the blade,
The angle of the tip ridge line portion is 60 [°] or more and 80 [°] or less, and the elastic blade longitudinal direction in the vicinity of the tip ridge line portion of the elastic blade when measured with a load of 1 [mN] by a Vickers indenter in the Martens hardness at a cross section perpendicular, 1.0 at an angle position from the tip edge line portion 70 [[mu] m] inside of the on the center line of the tip edge line [N / mm ^2] or more 5.0 [N / mm ² ] or less, and 0.4 [N / mm ² ] or more and 0.8 [N / mm ² ] or less at a position 140 [μm] inside from the tip ridge line portion on the center line, Cleaning blade. The cleaning blade according to claim 1 or 2,
The elastic blade is subjected to a low friction treatment in which the tip ridge portion is impregnated with at least one selected from an isocyanate compound, a fluorine compound, and a silicone compound, and the friction coefficient of the tip ridge portion is 0.5 or less. Characteristic cleaning blade. The cleaning blade according to claim 1, 2 or 3,
The cleaning blade is characterized in that the surface layer is made of an ultraviolet curable resin, and the layer thickness on the cut surface side of the surface layer is not less than 1 [μm] and not more than 50 [μm]. The cleaning blade of claim 1, 2, 3, or 4
A cleaning blade using a rubber containing a urethane group as the elastic blade. An image carrier;
Charging means for charging the surface of the image carrier;
A latent image forming means for forming an electrostatic latent image on the surface of the charged image carrier;
Developing means for developing an electrostatic latent image formed on the surface of the image carrier to form a toner image;
Transfer means for transferring the toner image on the surface of the image carrier to a transfer body;
In an image forming apparatus comprising a cleaning unit that has a cleaning blade that contacts the surface of the image carrier and removes residual toner attached to the surface of the image carrier.
6. An image forming apparatus using the cleaning blade according to claim 1, 2, 3, 4 or 5 as the cleaning blade. In a process cartridge that integrally supports an image carrier and cleaning means having a cleaning blade that removes at least residual toner adhered to the surface of the image carrier, and is detachable from the image forming apparatus main body,
6. A process cartridge using the cleaning blade according to claim 1, 2, 3, 4 or 5 as the cleaning blade. In an image forming method of forming a toner image on an image carrier, transferring the toner image from the image carrier to a transfer member, and then removing residual toner on the image carrier by a cleaning blade.
As the cleaning blade, a strip-shaped elastic blade, and a blade lower surface that is a surface facing the surface of the member to be cleaned of the elastic blade and a tip surface that is an end surface of the elastic blade in the longitudinal direction of the elastic blade. An elastic blade near the tip ridge line portion of the elastic blade when measured with a load of 1 [mN] by a Vickers indenter. Martens hardness in a cross section perpendicular to the longitudinal direction is 50 [μm] inside from the tip surface in the longitudinal direction of the elastic blade and 50 [μm] inside from the lower surface of the blade in a direction perpendicular to the longitudinal direction of the elastic blade 1.0 [N / mm ² ] or more and 5.0 [N / mm ² ] or less at a position of 100 [μm] in the longitudinal direction of the elastic body blade from the tip surface and the blade Use a cleaning blade that is 0.4 [N / mm ² ] or more and 0.8 [N / mm ² ] or less at a location 100 [μm] inside in a direction orthogonal to the longitudinal direction of the elastic blade from the lower surface of the blade. An image forming method. In an image forming method of forming a toner image on an image carrier, transferring the toner image from the image carrier to a transfer member, and then removing residual toner on the image carrier by a cleaning blade.
As the cleaning blade, a strip-shaped elastic blade, and a blade lower surface that is a surface facing the surface of the member to be cleaned of the elastic blade and a tip surface that is an end surface of the elastic blade in the longitudinal direction of the elastic blade. And a surface layer that is harder than the elastic blade and covers the tip ridge line portion, the angle of the tip ridge line portion is not less than 60 [°] and not more than 80 [°], and is loaded by the Vickers indenter 1 Martens hardness at the elastic blade section perpendicular to the longitudinal direction of the front edge portion near the elastic body blade when measured at [mN] is the tip edge line portion on the center line of the angle of the tip ridge portion It is 1.0 [N / mm ² ] or more and 5.0 [N / mm ² ] or less at a location inside 70 [μm], and 0. 0 at a location inside 140 [μm] from the tip ridge line portion on the center line. 4 [N / m Image forming method which comprises using a cleaning blade is ² or more 0.8 [N / mm ^2] or less.

Images